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  • 1980-1984  (1.691)
  • 1982  (1.691)
  • Cell & Developmental Biology  (962)
  • Chemical Engineering  (524)
  • Rat  (125)
  • Ultrastructure  (87)
  • Nuclear reactions
Datenquelle
Materialart
Erscheinungszeitraum
  • 1980-1984  (1.691)
Jahr
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    Correlations of the receptor content and ultrastructure of breast cancer cells (1982)
    Springer
    Archives of gynecology and obstetrics 231 (1982), S. 177-184 
    Details
    ISSN: 1432-0711
    Schlagwort(e): Steroid receptor ; Ultrastructure ; Breast cancer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Receptor assay results were compared with the ultrastructure of 127 breast cancers (112 primary tumors, six recurrent lesions, nine metastases). Tumors were considered to be receptor positive if the receptor levels were ⩾ 15 fmol/mg of soluble tissue protein. Most breast cancer had heterogenous cells with different grades of ultrastructural differentiation. A prevalence of well-differentiated cancer cells and an abundance of intracytoplasmic vacuoles had a significant correlation with a positive estrogen receptor status. The correlation was better than between malignancy grades and receptor content. The type of breast cancer and the menopausal status bore no relation to receptor content. Progesterone receptors were found in well-differentiated tumors of low malignancy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02110116
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  • 2
    Digitale Medien
    Digitale Medien
    Importance of catecholestrogens in the regulation of the ovarian cycle (1982)
    Springer
    Archives of gynecology and obstetrics 231 (1982), S. 315-320 
    Details
    ISSN: 1432-0711
    Schlagwort(e): Ovarian cycle ; Physiology ; Catecholestrogens ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Using highly stabilized catecholestrogen preparations-ascorbic acid added to the free alcohols or benzoic acid derivatives — 2- and 4-hydroxyestrogens were tested in simple, clearly defined animal models: As index for the peripheral action the influence on vaginal opening and uterus weight gain was monitored after continuous s.c. administration for 6 days (minipumps) in immature intact rats resulting in a relative estrogenic potency (estradiol = 100%) of 70–100% for 4-hydroxyestradiol and less than 30% for 2-hydroxyestradiol. As index for the central action LH levels were measured in adult ovx rats leading to the same relations in the relative potencies. As index for both central and peripheral actions LH levels and the formation of corpora lutea were investigated in animals with an intact but prepubertal feed-back loop, i.e. in 25-day-old immature rats. 4-Hydroxyestradiol in this model clearly triggered LH surges and induced ovulations, its potency being in the same range as that of estradiol. 2-Hydroxyestradiol, in comparable doses, again showed no significant effect. Finally, female immature animals known to ovulate 3 days after PMS injection were treated concomitantly with either primary or catecholestrogen-antibody preparations. Whereas the primary estrogen antibody significantly blocked ovulation, the 2- and 4-hydroxyestrogen antibodies were ineffective. If, however, PMS and estrogen-antibody treated animals were supplemented with 4-hydroxyestrogens, ovulations could be restored. Thereby, it was inferred that peripheral 4-hydroxyestrogens, though not essential for the physiology of reproduction, can completely replace the physiologically essential peripheral estradiol at central target sites.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02111730
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  • 3
    Digitale Medien
    Digitale Medien
    Interrelations of the rat's thalamic reticular and dorsal lateral geniculate nuclei (1982)
    Springer
    Experimental brain research 45 (1982), S. 217-229 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Rat ; Thalamic reticular nucleus ; Lateral geniculate nucleus ; Electrophysiology ; HRP
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Electrophysiological and neuroanatomical techniques have been used to study the properties of cells in the reticular nucleus of the thalamus (RNT) responsive to photic stimuli. In the rat these cells are located in a discrete region of the nucleus lying immediately rostral to the dorsal lateral geniculate nucleus (LGNd), where the visual field is represented in a retinotopic fashion. After injections of horseradish peroxidase (HRP) into this area, neurones labelled with reaction product were found in the LGNd and not in other thalamic relay nuclei. After HRP injections into the LGNd, labelled RNT cells were found only within the region which contains neurones responsive to photic stimuli. These observations suggest that there is a precise reciprocal relation between the two areas. Studies and comparisons of the responses of relay cells (P cells) in LGNd and cells in RNT to electrical shocks lead us to conclude that RNT cells receive their excitation mainly via those relay cells in LGNd which are themselves excited by fast-conducting retinal ganglion cell axons. Such cells in LGNd have phasic responses and concentric receptive fields while RNT cells have phasic responses and on/off fields and a comparison of the receptive field sizes of P cells and RNT cells suggests that only a small number of LGNd relay cells converge on to each RNT cell. Further, although a particular functional class of relay cells in LGNd (Y-type) is shown to provide the major input to visually responsive RNT cells, both Y type and W type relay cells are subject to their inhibitory control. These results furnish evidence that cells in the RNT have an important role in modulating the flow of visual information from the LGNd to cortex.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00235781
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  • 4
    Digitale Medien
    Digitale Medien
    Apomorphine-induced ipsilateral turning in rats with unilateral lesions of the parafascicular nucleus (1982)
    Springer
    Experimental brain research 47 (1982), S. 270-276 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Rat ; Turning ; Parafascicular nucleus ; Fasciculus retroflexus ; Apomorphine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Apomorphine, 2 mg/kg i.p., produced ipsilateral turning in rats with unilateral lesions in the parafascicular nucleus of the thalamus. The effect was completely blocked by the administration of haloperidol, 0.3 mg/kg i.p. There were no asymmetries by the lesions alone or after administration of haloperidol, 2 mg/kg i.p. to lesioned animals. In control experiments apomorphine produced a marked contralateral turning in animals with unilateral degeneration of the fasciculus retroflexus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00239386
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  • 5
    Digitale Medien
    Digitale Medien
    Die endokrinen Zellen des Verdauungsapparats (1982)
    Springer
    Journal of molecular medicine 60 (1982), S. 213-227 
    Details
    ISSN: 1432-1440
    Schlagwort(e): Gastrointestinal hormones ; Gastrointestinal neoplasms ; APUD cells ; Cytology ; Ultrastructure ; gastrointestinale Hormone ; gastrointestinale Tumoren ; APUD-Zellen ; Zytologie ; Ultrastruktur
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Endokrine Zellen kommen im Verdauungsapparat in Form von Mikro-Organen (Langerhans'sche Inseln) und als „diffuses endokrines epitheliales Organ“ (Feyrter), das heißt als im Epithelverband der Magendarmschleimhaut gelegene Einzelezellen vor. Diese gastro-entero-pankreatischen (GEP-) endokrinen Zellen synthetisieren neben Serotonin zahlreiche Polypeptidhormone, die zum einen systemisch wirken (Kohlenhydrat-Stoffwechsel) und zum andern der Regulierung der Verdauungstätigkeit dienen. Die vorliegende Übersicht befaßt sich vornehmlich mit der Zytologie und Zytochemie der GEP-endokrinen Zellen. Die bis heute bekannten 19 endokrinen Zelltypen werden entsprechend ihrem Verteilungsmuster nach der neuesten Nomenklatur synoptisch zusammengestellt. Außerdem werden morphologischfunktionelle Aspekte der Biologie, Pathologie und Zytogenese dieser Zellen sowie ihre Stellung innerhalb übergeordneter Systeme (APUD-Zellen, Paraneurone) diskutiert.
    Notizen: Summary Endocrine cells occur in the digestive system as micro-organs (islets of Langerhans) or scattered throughout the epithelium of the gastrointestinal tract (“diffuse endocrine epithelial organ” of Feyrter). These gastro-entero-pancreatic (GEP) endocrine cells synthesize — in addition to serotonin — a great variety of polypeptide hormones, which regulate both carbohydrate metabolism and digestive processes. The present review deals mainly with cytology and cytochemistry of GEP endocrine cells. A synopsis is presented of the 19 endocrine cell types identified to date, which includes their update nomenclature and their anatomical distribution pattern. Morphological-functional aspects of cell biology, pathology, and cytogenesis of these cells and their position within superimposed systems (APUD cells, paraneurons) are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01728340
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  • 6
    Digitale Medien
    Digitale Medien
    The effect of prenatal exposure to diazepam on aspects of postnatal development and behavior in rats (1982)
    Springer
    Psychopharmacology 78 (1982), S. 225-229 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Diazepam ; Prenatal treatment ; Development ; Discrimination ; Motor behavior ; Learning retention ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In the present study the effects of chronic treatment of pregnant rats with diazepam on the physical and behavioral development of their offspring were investigated. Rats that were diazepam-exposed prenatally were compared to age-matched controls in terms of the following: number of littermates; birth weight and weight gain until weaning; motor development and coordination; simple motor learning; open field activity; performance on learning tasks of varving complexity; retention of these tasks. Nulliparous Wistar rats were injected s.c. for 16 days of their pregnancy with either 2.5, 5, or 10 mg/kg diazepam or an equal volume of vehicle. Prenatal diazepam treatment did not alter litter size, birth weight, or the righting reflex, but seemed to retard early motor development transiently. Diazepam pups showed longer latencies and less rearing in the open field. There were no differences between animals exposed to drug and vehicle in simple motor learning or in acquiring a simple successive discrimination task. However, there were significant dosedependent differences on a complex six-choice simultaneous discrimination learning task, the diazepam-exposed rats making more errors and taking more time to reach the goal. A significant difference was seen again between diazepam-and vehicle-exposed rats on the retention test 10 days later. The results indicate that diazepam administered to pregnant rats has long-range effects on the behavior of the offspring, some becoming manifest even in maturity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00428155
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  • 7
    Digitale Medien
    Digitale Medien
    Adamantinoma of bone (1982)
    Springer
    Virchows Archiv 398 (1982), S. 75-86 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Bone neoplasms ; Adamantinoma ; Ultrastructure ; Immunoenzyme ; Tibia/fibula ; Keratin ; Blood group antigens ; Factor VIII-related antigen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Adamantinoma of bone is a rare tumor, and fine structural analysis has been done in only a few cases. We report four cases studied by electron microscopy and immunohistochemical methods. Ultrastructural evaluation revealed a characteristic constellation of features, including intracellular bundles of type I microfilaments, moderate numbers of evenly dispersed mitochondria, scattered profiles of rough endoplasmic reticulum, occasional Golgi bodies and lysosomes, and scattered glycogen particles. Microvillous processes and desmosomes were identified in all tumors. Well-formed basement membranes enveloped cell clusters but did not surround individual cells. Intercellular basement membrane-like material also was found focally in pools. Ultrastructural features of endothelial differentiation, including Weibel-Palade bodies, micropinocytotic vesicles, and tight junctions, were not identified. Immunoperoxidase stains for coagulation factor VIII (von Willebrand factor) and blood group antigens were negative, whereas similar stains for keratin were positive. Our findings strongly suggest that adamantinoma is a neoplasm expressing definite epithelial, rather than endothelial, characteristics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00585615
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  • 8
    Digitale Medien
    Digitale Medien
    The pars tuberalis of the human pituitary (1982)
    Springer
    Virchows Archiv 399 (1982), S. 49-59 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Pituitary ; Pars tuberalis ; Gonadotrophs ; Squamous nests ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Forty autopsy pituitaries were studied to elucidate the histology, immunocytology and ultrastructure of pars tuberalis in subjects with normal and abnormal endocrine homeostasis. Pars tuberalis consisted mainly of gonadotrophs interspersed with few corticotrophs and thyrotrophs, histologically resembling those of pars distalis. Somatotrophs and lactotrophs were not identified. There were no histologic differences attributable to age or sex. In cases of glucocorticoid excess, pars tuberalis corticotrophs showed Crooke's hyalinization. Following castration or hypophysectomy, pars tuberalis gonadotrophs exhibited more intense immunostaining for FSH1 and LH than did normals. Ultrastructural analysis revealed gonadotrophs and corticotrophs showing no evidence of active secretion; immunoelectron microscopy demonstrated FSH, LH and ACTH in secretory granules. By light microscopy, squamous nests, often identified in pars tuberalis, were positive for immunoreactive keratin; cells at their periphery contained FSH, LH or ACTH, indicating derivation of nests by squamous metaplasia from gonadotrophs and corticotrophs. By electron microscopy, clusters of epithelial cells containing desmosomes and tonofilaments were surrounded by granulated gonadotrophs. Human pars tuberalis cells represent mainly a subpopulation of gonadotrophs possessing all organelles required for synthesis and storage of hormones but showing ultrastructural features of functional inactivity; the reasons for this inactivity and for the formation of squamous nests remain unexplained.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00666218
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  • 9
    Digitale Medien
    Digitale Medien
    Ultrastructure of myocardium in the hurler syndrome (1982)
    Springer
    Virchows Archiv 394 (1982), S. 195-205 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Hurler syndrome ; Myocardium ; Histochemistry ; Ultrastructure ; Storage of gangliosides
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Cardiac tissues obtained at post mortem examination of eight patients with the Hurler syndrome, who ranged in age from 5 to 23 years, were examined by histochemical methods and electron microscopy. Extensive myocardiocytic vacuolization and increased interstitial fibrous tissue were noted by light microscopy in all hearts. The cytoplasmic (perinuclear) vacuoles contained Luxol-fast-blue-positive substance. At the ultrastructural level, abnormal cytoplasmic organelles were present within the myocardiocytes in all patients. These organelles were of three types: zebra bodies (ZB), membranous cytoplasmic bodies (MCB) and granulomembranous bodies (GMB). As ZB and MCB are believed to represent the morphological counterpart of accumulated gangliosides, these substances rather than glycosaminoglycans appear to be stored within myocardiocytes of patients with the Hurler syndrome. The accumulation of gangliosides and the consequent damage to the myocardial substratum probably contributes to the clinically evident cardiac disease, so often observed in the patients with this disorder.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00430665
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  • 10
    Digitale Medien
    Digitale Medien
    Pituitary adenomas with hyperfunction of TSH (1982)
    Springer
    Virchows Archiv 394 (1982), S. 255-267 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Pituitary ; Adenoma ; TSH ; Ultrastructure ; Immunocytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In a collection of 564 surgically removed pituitary adenomas, 4 cases were found to have had elevated TSH plasma levels. One of these tumors (case 1) could be classified as a highly differentiated mucoid TSH cell adenoma presenting histochemical reactions typical of, as well as electron microscopical features identical to, normal TSH cells. Immunoenzymatic studies failed to demonstrate TSH in the tumor cells. Two further adenomas (case 2 and 3) were similarly structured in many areas, but showed regions of poorer differentiation in which cells with distinct pleomorphism, irregular secretory granules, increased numbers of ribosomes and a well developed rough endoplasmic reticulum were present. In 10% of the tumor cells GH could be demonstrated immunoenzymatically, but there was no TSH. The fourth adenoma was an undifferentiated acidophilic adenoma showing pleomorphic cells having slight acidophil and partly mucoid granulations. The ultrastructure showed convoluted nuclei, increased numbers of free ribosomes as well as abundant rough endoplasmic reticulum and secretory granules which were different in size and number but distinctly of the TSH cell type. Immunoenzymatically, TSH was found in some cells, with GH in more cells. Endocrinologically, elevated levels of GH were measured in cases 2, 3 and 4 with LH being increased in case 1. Clinical and morphological correlations are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00430669
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  • 11
    Digitale Medien
    Digitale Medien
    Aneurysmal bone cyst, a study of ultrastructure and malignant transformation (1982)
    Springer
    Virchows Archiv 395 (1982), S. 169-179 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Aneurysmal bone cyst ; Malignant transformation ; Osteosarcoma ; Irradiation ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Four cases of aneurysmal bone cyst, of which one became malignant 7 years after irradiation, were studied by electron microscopy. The aneurysmal bone cyst was composed of four different types of stromal cells — fibroblasts, myofibroblasts, osteoblasts, and histiocytes — and osteo-clastlike multinucleated giant cells. The surface of blood spaces was devoid of specialized endothelium, which may explain the presence of large quantities of extravasated erythrocytes. Some histiocytes contained siderosomes. The malignant lesion consisted of two main types of stromal cells, of which one had electron lucent and the other electron dense cytoplasm. The stromal cells produced osteoid and the tumour was regarded as an osteosarcoma. The multinucleated giant cells resembled those observed in aneurysmal bone cysts, but the nuclei seemed to be more often spherical. It is concluded that irradiation of the aneurysmal bone cyst may cause sarcomatous transformation in a cell capable of producing osteoid.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00429610
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  • 12
    Digitale Medien
    Digitale Medien
    Elastofibroma (1982)
    Springer
    Virchows Archiv 396 (1982), S. 127-140 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Elastin ; Elastofibroma ; Histochemistry ; Soft tissue tumor ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Four cases of elastofibroma located in the subscapular region of 3 men aged 66, 74, and 83 years, and a woman 70 years old are reported. A correlated light and electron microscopic study including ultrastructural examination of Verhoeff's iron-hematoxylin (VIH)-stained sections was performed. Light microscopically, the elastofibromas were characterized by connective tissue built up by collagen fibers and sclerotic masses mingled with numerous fibers and globules of elastin material. In one micron thick Epon sections these elastin fibers often revealed a central axis surrounded by a mantle composed of periodic segments giving them a necklace-like appearance. The ultrastructural findings of these elastin structures, stained with VIH, and the appearance of the stroma cells and their relation to the elastin indicate that elastofibroma is a non-neoplastic reactive lesion in which elastin material is synthesized by the stromal cells and predominantly laid down around preexisting elastic fibers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00431236
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  • 13
    Digitale Medien
    Digitale Medien
    Ultrastructural study of conventional chondrosarcomas and myxoid- and mesenchymal-chondrosarcomas (1982)
    Springer
    Virchows Archiv 396 (1982), S. 197-211 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Chondrosarcoma ; Mesenchymal ; Myxoid ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Five cases of conventional chondrosarcomas (CS.) of graded malignancy, 3 cases of myxoid CS. and 2 cases of mesenchymal CS. were studied by electron-microscopy. The chondrocyte like tumor cells of conventional CS. were characterized by: an ovoid shape, eccentric nucleus, abundant endoplasmic reticulum with dilated cisternae of RER; cytoplasmic glycogen, lipid droplets, and filaments plus numerous thin cytoplasmic projections. The histologically high grade tumors showed fewer cytoplasmic organelles, bizarre nuclei and more prominent nucleoli than the better differentiated ones. The tumor cells of myxoid CS. were chiefly fusiform. The cells frequently presented a pattern of rows with good cellular cohesion, and scanty cytoplasmic projections. The most prominent cytoplasmic feature was a conspicuous RER. Abundant cytoplasmic filaments and cytoplasmic glycogen were also observed. The undifferentiated areas of the mesenchymal CS. showed primitive mesenchymal cells with rounded nuclei, and scanty cytoplasm which was poor in organelles and glycogen. The cytoplasmic membranes were very cohesive and cytoplasmic projections were not present. Scanty cytoplasmic filaments and conspicuous desmosome like junctions were observed. The intercellular matrix of conventional and myxoid CS. consisted of fibrils, glycosaminoglycan granules and collagen fibers. In the undifferentiated zones of the mesenchymal CS. the intercellular matrix was very scanty and did not contain collagen fibrils. The more immature cells correspond to the small undifferentiated cells of mesenchymal chondrosarcoma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00431241
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  • 14
    Digitale Medien
    Digitale Medien
    Papillary mesothelioma of the tunica vaginalis propria testis (1982)
    Springer
    Virchows Archiv 396 (1982), S. 231-238 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Mesothelioma ; Testis ; Ultrastructure ; Clear cell
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Ultrastructural features of a papillary mesothelioma arising in a hydrocele-sack are reported. The tumour cells presented numerous microvilli, desmosomes, basement membranes and abundant bundles of microfilaments, which all are hallmarks of mesotheliomas. The predominant cell type was the “clear epithelial cell”, but transitional cells and degenerative forms (foamy cells) were also found. The morphology and differential diagnosis of mesothelial tumours arising in the tunica vaginalis propria testis are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00431244
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  • 15
    Digitale Medien
    Digitale Medien
    Epithelioid sarcoma (1982)
    Springer
    Virchows Archiv 397 (1982), S. 109-119 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Epithelioid sarcoma ; Ultrastructure ; 5′-nucleotidase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A case of epithelioid sarcoma was studied by electron microscopy and by light and electron microscopic enzyme histochemistry comparing with several control soft tissues. In addition to previously reported ultrastructural features, such as abundant 10 nm cytoplasmic filaments, desmosome-like cell junctions and small cystic spaces surrounded by filopodia or microvilli of the tumor cells, we encountered 10 nm cytoplasmic filaments showing electron dense condensation with a concentrically oriented or whorled pattern and a finger-print-like arrangement and 5′-nucleotidase activity of tumor cell membrane. Among the control soft tissues, 5′-nucleotidase activity was found only in synovial and endothelial cells. Both tumor and synovial cells showed no activity of adenosine triphosphatase, while marked activity of the enzyme was found in endothelial cells. These results support the concept that epithelioid sarcoma is derived from mesenchymal cells undergoing differentiation toward synovial cells during neoplastic transformation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00430898
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  • 16
    Digitale Medien
    Digitale Medien
    Microvasculature of human colorectal epithelial tumors (1982)
    Springer
    Virchows Archiv 397 (1982), S. 131-147 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Colonic neoplasm ; Microcirculation ; Ultrastructure ; Pathology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The ultrastructure of the microvasculature in human colorectal adenomas and carcinomas was studied, and compared with that of normal tissue. Blood vessels in adenomas were generally of normal structure, whereas carcinoma vessels displayed a variety of structural alterations. Endothelial proliferation was frequently observed in all the eleven carcinomas examined, which confirms the reports of new vessel formation in experimental malignant tumors. The presence of fenestrations in obviously abnormal endothelium was tentatively attributed to hypoxia, vascular regression or immaturity of the cells, in spite of the fact that normal capillaries in colonic mucosa are fenestrated. Some vessels showed multilayered basement membranes, various types of activated cells containing numerous lysosomal granules, and thickened perivascular tissue. These features may be a vascular response to repeated damage or a manifestation of vascular remodelling. Dilated thin-walled vessels, which were usually found at the periphery of carcinomas, were identified as venules. Small vessels located between the closely apposed carcinoma tubules were not obviously abnormal. They were nevertheless considered to be tumor-induced vessels which had undergone differentiation. The differences in vascular morphology between adenomas and carcinomas were considered to be due to their different growth patterns, growth rates and degrees of maturity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00442384
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  • 17
    Digitale Medien
    Digitale Medien
    A study of the role of the cholinergic system in amygdaloid kindling in rats (1982)
    Springer
    Psychopharmacology 76 (1982), S. 66-69 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Experimental epilepsy ; Kindling ; Amygdala ; Acetylcholine ; Choline uptake ; Atropine ; Muscarinic receptors ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The effect of atropine on kindling the amygdala of rats was tested by administering the drug in a dose of 25 mg/kg 1 h before each stimulus was applied. Rats tested with atropine kindled at the same rate as saline-treated controls. Cholinergic activity in the amygdala of rats was assessed, 4 weeks after the completion of kindling, by measuring both muscarinic receptor numbers and sodium-dependent high affinity choline uptake in tissue homogenates. There was no change in either of these parameters attributable to kindling. These results suggest that changes in the cholinergic system are not fundamental either to the development or the maintenance of kindling in the rat amygdala.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00430758
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  • 18
    Digitale Medien
    Digitale Medien
    Reduced brain serotonergic activity after repeated treatment with β-adrenoceptor antagonists (1982)
    Springer
    Psychopharmacology 76 (1982), S. 114-117 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Brain ; β-Adrenoceptors ; Serotonin synthesis ; Metoprolol ; ICI 118,551 ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Rats were treated subchronically (14 days) or acutely (single dose) with the β1-selective adrenoceptor antagonist metoprolol or the β2-selective adrenoceptor antagonist ICI 118,551. Metoprolol (350 mg/kg/day for 14 days, orally) significantly reduced the 5-hydroxytryptophan (5-HTP) accumulation when measured 30 min after inhibition of L-amino acid decarboxylase by NSD 1015 (100 mg/kg IP) in the limbic forebrain, the corpus striatum, the cerebral cortex, the brain stem, and in the cerebellum. ICI 118,551 (0.5 mg/kg, twice daily for 14 days, SC) also significantly reduced the 5-HTP accumulation in the same brain regions except in the corpus striatum and the brain stem. Simultaneously assayed tryptophan levels were largely unaffected. Thus sustained β-adrenoceptor blockade causes a decrease in the in vivo rate of tryptophan hydroxylation in various rat brain regions. The subchronic treatments with metoprolol or ICI 118,551 also significantly reduced the endogenous levels of 5-hydroxytryptamine (5-HT) in the various rat brain regions studied. Acute treatment with either metoprolol (2 mg/kg SC) or ICI 118,551 (0.5 mg/kg SC) did not affect the 5-HTP accumulation or the endogenous 5-HT levels in the brain regions studied. This inhibitory effect on brain 5-HT systems produced by sustained β-adrenoceptor blockade may be of significance both for the long-term cardiovascular action and for occasional neuropsychiatric side effects during β-blocking therapy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00435263
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  • 19
    Digitale Medien
    Digitale Medien
    Effects of chronic nicotine administration on the response and adaptation to stress (1982)
    Springer
    Psychopharmacology 76 (1982), S. 160-162 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Nicotine ; Withdrawal ; Plasma corticosterone ; Stress ; Adaptation ; 5-Hydroxytryptamine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The effects of chronic nicotine administration (0.4 mg/kg for 40 days) and its withdrawal on the adrenocortical response to acute and repeated exposure to stress have been examined and related to changes in brain 5-hydroxyindole levels. No significant effects on the response to acute stress were observed. Repeated exposure to the stressful procedure resulted in complete adaptation of the adrenocortical response and the development of a significant (P〈0.01) positive correlation between the plasma corticosterone and hippocampal 5-HT concentrations. In nicotine-treated rats, complete adaptation did not occur and the plasma corticosterone showed a significant (P〈0.05) negative correlation with hippocampal 5-HT. Nicotine withdrawal was not associated with any reduction in plasma corticosterone, but did abolish its relationship with hippocampal 5-HT.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00435271
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  • 20
    Digitale Medien
    Digitale Medien
    Involvement of a central dopaminergic system in 5-methoxy-N,N-dimethyltryptamine-induced turning behaviour in rats with lesions of the dorsal raphé nuclei (1982)
    Springer
    Psychopharmacology 78 (1982), S. 261-265 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Turning behaviour ; Brain lesions ; 5-MeODMT ; Dopaminergic system ; Dopamine release ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The turning behaviour induced by 5-methoxy-N,N-dimethyltryptamine (5-MeODMT) has been investigated in rats with lesions of the dorsal raphé nucleus (DRN). 5-MeODMT caused a dose-related contralateral turning in rats with 5,7-dihydroxytrypamine (5,7-DHT) lesions of the substantia nigra and a similar effect was observed in DRN-lesioned rats. In contrast, a dose-related ipsilateral turning was observed when 5-MeODMT was injected into rats with 5,7-DHT lesions of the striatum. These results suggest that the effects of 5-MeODMT in DRN-lesioned rats are mediated via the substantia nigra. The contralateral turning induced by 5-MeODMT in rats with a 5,7-DHT lesion of the DRN was significantly reduced when a second 6-hydroxydopamine lesion was placed in the striatum, but not when it was placed in the nucleus accumbens. Thus the nigrostriatal dopaminergic system seems to be involved in 5-MeODMT-induced turning. The release of tritium from slices of substantia nigra previously labelled with [3H]-dopamine was inhibited by 5-MeODMT (10-7 to 10-5 M) and this effect was blocked by methysergide in a concentration-related manner. Tetrodotoxin (10-7M) failed to antagonise 5-MeODMT. These results suggest that 5-MeODMT can inhibit dopamine release from nigral dendrites, which could in turn enhance nigrostriatal activity by reducing the auto-inhibitory actions of dopamine, thereby causing contralateral turning in DRN-lesioned rats.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00428162
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  • 21
    Digitale Medien
    Digitale Medien
    Does conditioned nausea mediate drug-induced conditioned taste aversion? (1982)
    Springer
    Psychopharmacology 78 (1982), S. 277-281 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Conditioned taste aversion ; Scopolamine ; Prochlorperazine ; Lithium ; Amphetamine ; Morphine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Two antiemetic drugs were tested on the expression of taste aversions previously conditioned in rats with lithium, amphetamine or morphine. Neither prochlorperazine nor scopolamine administered prior to testing attenuated established aversions, although both drugs are known to have antiemetic effects in other species. Negative findings were obtained with a range of doses of prochlorperazine and scopolamine, with strong and weak aversions, with one- and two-stimulus tests, in a repeated one-stimulus extinction procedure, with between- and within-group designs and with hooded, albino, male and female rats. The results do not support the widely accepted hypothesis that conditioned nausea mediates conditioned taste aversion.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00428165
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  • 22
    Digitale Medien
    Digitale Medien
    Lack of evidence for a role of endorphinergic mechanisms in mediating a discriminative stimulus produced by diazepam in rats (1982)
    Springer
    Psychopharmacology 78 (1982), S. 282-284 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Discriminative stimulus ; Diazepam ; Morphine ; Naloxone ; Endorphins ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Male Sprague-Dawley rats were trained in a two-lever food-reinforced procedure to discriminate between the effect of saline and diazepam (2.5 mg/kg). After acquisition of this discrimination, the ability of morphine to generalize, and naloxone to antagonize the diazepam discriminative stimulus was tested. The rats did not generalized the effect of morphine, and naloxone did not antagonize the diazepam discriminative stimulus whether it was given prior or subsequent to diazepam. These data suggest a lack of involvement of endorphins in mediating the discriminative stimulus property of diazepam.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00428166
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  • 23
    Digitale Medien
    Digitale Medien
    Using Ro 15-1788 to investigate the benzodiazepine receptor in vivo: Studies on the anticonvulsant and sedative effect of melatonin and the convulsant effect of the benzodiazepine Ro 05-3663 (1982)
    Springer
    Psychopharmacology 78 (1982), S. 293-295 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Seizure threshold ; Ro 15-1788 ; Ro 05-3663 ; Benzodiazepine receptor ; Melatonin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Both the anticonvulsant and sedative effects of diazepam (5 mg/kg) were reversed by subsequent administration of the suggested specific benzodiazepine antagonist Ro 15-1788. In contrast neither the seizure threshold raising or sedative effect of melatonin (200 mg/kg) was reversed by Ro 15-1788. Ro 15-1788 had no effect on the convulsant action of the benzodiazepine Ro 05-3663. These data therefore argue against the suggestion that melatonin produces its sedative and anticonvulsant effects in vivo by interacting with the benzodiazepine receptor, and also strengthens the suggestion that Ro 05-3663 does not act at this site. The use of Ro 15-1788 in demonstrating whether a drug acts in vivo at the benzodiazepine site to produce a pharmacological response is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00428169
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  • 24
    Digitale Medien
    Digitale Medien
    Influence of lisuride on morphine withdrawal signs in the rat: A dopamine-mimetic effect (1982)
    Springer
    Psychopharmacology 78 (1982), S. 326-330 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Morphine withdrawal ; Dopamine ; Lisuride ; N-n-propylnorapomorphine ; Haloperidol ; Sulpiride ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The influence of lisuride on naloxone-induced withdrawal signs (wet shakes, escape attempts) was studied in morphine-dependent rats. Lisuride, injected IP at doses of 12.5 and 25 μg/kg, inhibited wet shakes while not significantly altering escape attempts induced by naloxone (4 mg/kg IP). At higher doses (50 and 100 μg/kg IP), lisuride's inhibitory effect on wet shakes persisted while escape attempts were actually potentiated with respect to control withdrawal rats. Increases in aggressive behavior were seen at all doses, and were dose-related. Haloperidol (0.3 mg/kg IP), administered 40 min before lisuride, did not modify the antagonistic effect on wet shakes, unlike sulpiride (40 mg/kg IP 30 min before lisuride), but at the same time blocked the increase in escape attempts and aggressiveness induced by lisuride. We suggest that lisuride modulates withdrawal signs by stimulation of dopamine receptors in the CNS. The effect of the dopamine mimetic N-n-propylnorapomorphine (NPA) on the same variables is reported as well as the influence of haloperidol on NPA, and a comparison between the effects of the two drugs is made.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00433735
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  • 25
    Digitale Medien
    Digitale Medien
    Feeding stimulated by very low doses of d-amphetamine administered systemically or by microinjection into the striatum (1982)
    Springer
    Psychopharmacology 78 (1982), S. 336-341 
    Details
    ISSN: 1432-2072
    Schlagwort(e): d-Amphetamine ; Feeding ; Locomotion ; Stereotypy ; Striatum ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The effects of d-amphetamine over a wide range of doses (0.125–4.0 mg/kg IP) on rat unconditioned behaviour were examined in the presence of food and water (experiment 1), in their absence (experiment 2) and after microinjection (2.0 μg in 0.5 μl) directly into the striatum (experiment 3). In experiment 1 very low doses (0.125 and 0.25 mg/kg) stimulated the intake of food, but not water, and higher doses produced locomotor hyperactivity, rearing, stereotyped sniffing and anorexia. In experiment 2 all doses, including very low doses (0.125 and 0.25 mg/kg), significantly potentiated locomotor activity. In experiment 3, microinjection into the corpus striatum elicited substantial feeding, but not drinking, locomotor activity or stereotyped behaviour. The results suggest that a single graded facilitative mechanism underlies the effects on food intake and other behavioural effects of amphetamine, as implied by a general hypothesis of amphetamine action proposed in the literature, and that these effects may to a large extent by mediated by forebrain dopamine systems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00433737
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  • 26
    Digitale Medien
    Digitale Medien
    Effects of lithium on behaviour induced by phencyclidine and amphetamine in rats (1982)
    Springer
    Psychopharmacology 78 (1982), S. 373-376 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Phencyclidine ; d-amphetamine ; Lithium ; Locomotor activity ; Stereotyped behaviors ; Ataxia ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract d-Amphetamine and phencyclidine (PCP) have both been reported to produce manic-like sequela in humans, effects that are reportedly antagonized by lithium. To test the hypothesis that the acute effects of these drugs in rats may serve as models of mania, the behaviors, induced by d-amphetamine (3 mg/kg) or PCP (5 mg/kg) were quantified on behavioral rating scales subsequent to chronic dietary pretreatment with lithium carbonate or control diet. On day 14 of pretreatment, PCP-induced stereotyped behaviors and ataxia were potentiated in rats receiving lithium (plasma levels 1.0±0.23 mEq/l). PCP-induced locomotor activity was not affected by lithium pretreatment. Stereotypies and locomotion induced by d-amphetamine were also not significantly affected by lithium pretreatment. These results suggest that neither PCP nor amphetamine administered acutely to rats will be useful models to explore the manic-like symptoms produced by these drugs in humans.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00433745
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  • 27
    Digitale Medien
    Digitale Medien
    GABAergic mechanisms within the ventral tegmental area: Involvement of dopaminergic (A 10) and non-dopaminergic neurones (1982)
    Springer
    Psychopharmacology 77 (1982), S. 186-192 
    Details
    ISSN: 1432-2072
    Schlagwort(e): GABA ; Ventral tegmental area ; Dopamine ; Pictrotoxin ; EOS ; Enkephalin ; Locomotor activity ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The spontaneous activity of rats was measured after activation or inhibition of GABA activity in the ventral tegmental area of the midbrain (VTA). Six hours after bilateral injection of ethanolamine-o-sulphate (GABA agonist) into the VTA, the behavioural activation induced either by d-amphetamine (amph) or by bilateral VTA infusion of a long-lasting enkephalin analogue was completely blocked. Bilateral infusion of picrotoxin (GABA antagonist) into the VTA elicited a short-lived (40 min) dose-dependent behavioural activation which was not reduced either by prior specific lesion of the meso-cortico-limbic dopaminergic neurones or by administration of the opiate antagonist naloxone. Moreover, the simultaneous administration of picrotoxin and amph induced complex changes in behaviour which consisted of additive effects during the first 40 min, followed by an inhibition of the activating effect of amph. Our findings indicate that GABA-mediated inhibition involves both dopaminergic and non-dopaminergic neurones within the VTA, and possible implications for human pathology are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00431946
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  • 28
    Digitale Medien
    Digitale Medien
    The effect of tryptamine on serotonin release from hypothalamic slices is mediated by a cholinergic interneurone (1982)
    Springer
    Psychopharmacology 78 (1982), S. 85-88 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Hypothalamus ; Serotonin ; Tryptamine ; Acetylcholine ; Release ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Tryptamine produced a concentration-related inhibition of potassium-evoked release of tritium from slices of rat hypothalamus preloaded with 3H-serotonin. This effect of tryptamine was blocked by a series of serotonin antagonists with a relative order of potency which suggested that tryptamine was acting on a post-junctional serotonin receptor. However, the response to tryptamine was also blocked by tetrodotoxin, indicating that tryptamine may be acting indirectly via the release of a second neurotransmitter. The finding that physostigmine enhanced, whilst atropine antagonised the effect of tryptamine suggests that the second neurotransmitter may be acetylcholine. This possibility is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00470595
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  • 29
    Digitale Medien
    Digitale Medien
    3H-imipramine high-affinity binding sites in rat brain. Effects of imipramine and lithium (1982)
    Springer
    Psychopharmacology 77 (1982), S. 94-97 
    Details
    ISSN: 1432-2072
    Schlagwort(e): 3H-imipramine binding site ; Imipramine ; Lithium ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The specific high-affinity binding of 3H-imipramine to rat brain membranes was investigated. Five weeks of lithium treatment decreased the number of binding sites, but had no effect on the affinity constants. Long-term imipramine treatment had no effect on the number of binding sites but apparently decreased the affinity. The latter effect was probably due to imipramine remaining in the membrane preparation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00436105
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  • 30
    Digitale Medien
    Digitale Medien
    Isoprenaline increases brain concentrations of administered l-dopa and l-tryptophan in the rat (1982)
    Springer
    Psychopharmacology 77 (1982), S. 98-100 
    Details
    ISSN: 1432-2072
    Schlagwort(e): l-dopa ; Tryptophan ; Brain concentration ; Isoprenaline ; Carrier transport ; Blood-brain barrier ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A small dose of isoprenaline or saline was administered intraperitoneally to rats 20 min before the administration of one of the amino acids l-dopa or l-tryptophan. Isoprenaline caused a marked increase in the brain concentration of the administered amino acid. Isoprenaline has previously been shown to cause a decrease in at least some of those plasma amino acids which compete with l-dopa and tryptophan for carrier-mediated transport into the brain. The effect of isoprenaline on the concentrations of dopa and tryptophan in the brain is suggested to be at least partly caused by a change in the relationship between endogeneous and administered amino acids. It is also possible that a direct effect of isoprenaline on the blood-brain barrier transport system contributes to the effect. The reported finding might be of clinical interest in view of the therapeutic importance of aromatic amino acids with a central site of action.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00436106
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  • 31
    Digitale Medien
    Digitale Medien
    Residual effects of prolonged cannabis administration on exploration and DRL performance in rats (1982)
    Springer
    Psychopharmacology 77 (1982), S. 124-128 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Chronic cannabis ; Locomotor activity ; DRL performance ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Chronic oral administration of cannabis extract to rats (daily Δ 9 dose 20 mg/kg) was examined for its residual effect on open field activity and DRL (differential reinforcement of low-rate responding) performance, following a 2–3-month drug-free period. Locomotor activity during the latter part of an open field test was markedly increased in rats previously treated for either 6 months or 3 months with the drug. The same treatments also produced a significant impairment on a DRL-20 task relative to control subjects' performance. These and other findings (impaired maze learning and facilitated two-way shuttle box avoidance) might mean that cannabis produces long-lasting hippocampal, dysfunction in rats.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00431933
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  • 32
    Digitale Medien
    Digitale Medien
    Learning impairment in the radial-arm maze following prolonged cannabis treatment in rats (1982)
    Springer
    Psychopharmacology 77 (1982), S. 117-123 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Chronic cannabis ; Learning ; Radial-arm maze ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Chronic oral administration of cannabis extract to rats (daily Δ 9tetrahydrocannabinol dose 20 mg/kg) was examined in three experiments for its residual effect on radialarm maze learning following a 1-month drug-free period. Learning a simple eight-arm maze was significantly impaired in rats treated for either 6 months (Experiment I) or 3 months (Experiment II) with the drug. In Experiment III, animals that received the extract for 3 months exhibited significant learning deficits on a much more difficult 12-arm radial maze. The results demonstrate that the deleterious effects of cannabis on radial-arm maze learning are probably due to a tendency toward increased vigilance and perseveration, possibly combined with an impaired utilization of spatial cues.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00431932
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  • 33
    Digitale Medien
    Digitale Medien
    Oral dyskinesia in rats following brain lesions and neuroleptic drug administration (1982)
    Springer
    Psychopharmacology 77 (1982), S. 134-139 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Animal model ; Rat ; Tardive dyskinesia ; Oral dyskinesia ; Chronic haloperidol ; Neuroleptic ; 6-Hydroxydopamine ; Kainic acid ; Frontal cortex ; Striatum
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract After 10–12 weeks of chronic haloperidol administration rats with frontal cortex ablations or lesions induced by intracerebroventricular injection of 6-hydroxydopamine developed vacuous chewing behavior at a fairly stable frequency (bifrontal ablations had 15–20, 6-hydroxy-dopamine lesioned rats 7–12 chewing movements/min). This behavior persisted for 10 weeks after the last injection of haloperidol decanoate. However, rats with frontal cortex lesions developed a low rate of vacuous chewings (4–8 chewings/min) even without haloperidol administration. Bilateral intrastriatal injections of kainic acid in combination with chronic haloperidol administration did not cause chewing movements in excess of unlesioned haloperidol-treated controls. Pharmacological tests of this animal model for tardive dyskinesia (TD) revealed similarities to human TD, but also differences. Dopamine agonists (apomorphine) and antagonists (haloperidol) both lowered chewing behavior analogous to reported effects on TD and so did gabaculine. The cholinergic drugs physostigmine and pilocarpine, however, increased chewing in rats, while anticholinergics (atropine) reduced it, in contrast to reported effects on human TD.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00431935
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  • 34
    Digitale Medien
    Digitale Medien
    Locomotor activity of rats after stimulation of the nucleus locus coeruleus region or after lesion of the dorsal noradrenergic bundle: Effects of clonidine, prazosin and yohimbine (1982)
    Springer
    Psychopharmacology 78 (1982), S. 239-244 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Locus coeruleus ; Dorsal noradrenergic bundle ; Open-field ; Clonidine ; Prazosin ; Yohimbine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract We previously showed in the rat that electrical stimulation of the nucleus locus coeruleus produced, 4 weeks later, a significant increase in the number of α1 and α1 in the cerebral cortex. In a parallel pharmacological study, we tested the effects of small doses of clonidine on the locomotor activity of stimulated rats and implanted but not stimulated animals. In stimulated rats only, clonidine had a dual effect: firstly, sedation 30 min after injection, and secondly, hyperactivity which was observed 24 h after injection. In the present study, using the same behavioral paradigm, we tested the effects of small doses of clonidine on the locomotor activity of three groups of rats: stimulated in the locus coeruleus, lesioned in the dorsal noradrenergic bundle and controls. In stimulated rats injected with clonidine, delayed hyperactivity appeared 24 h after the injection, beginning at the smallest dose used (2.5 μg/kg). This hyperactivity was not due to the stimulation per se, since it did not appear in stimulated rats injected with the vehicle. In rats with dorsal noradrenergic bundle lesions, this delayed hyperactivity was observed only after a high dose (50 μg/kg) of clonidine. In a second experiment, we tested the effect of small doses of prazosin or of yohimbine on the delayed, drug-induced, hyperactivity of stimulated or lesioned rats. In stimulated rats, prazosin (an α1-adrenoceptor antagonist) suppressed the hyperactivity produced by clonidine. Yohimbine (an α2-adrenoceptor antagonist) markedly increased the locomotor activity of stimulated rats injected with vehicle. Likewise, in lesioned rats, prazosin suppressed the hyperactivity produced by a dose of 50 μg/kg of clonidine. These results are interpreted in relation to the possible role of α-adrenoceptors in the regulation of locomotor activity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00428158
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  • 35
    Digitale Medien
    Digitale Medien
    Antagonism of the anticonflict effects of chlordiazepoxide by β-carboline carboxylic acid ethyl ester, Ro 15-1788 and ACTH(4–10) (1982)
    Springer
    Psychopharmacology 78 (1982), S. 256-260 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Anxiety ; Punishment ; Conflict ; Chlordiazepoxide ; β-Carboline carboxylic acid ethyl ester ; Ro 15-1788 ; ACTH(4–10) ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The antagonism of the anticonflict effect of chlordiazepoxide (CDP) by β-carboline carboxylic acid ethyl ester (BCCE), Ro 15-1788 and ACTH(4–10) has been evaluated in the Geller-Seifter rat conflict test in which CDP increases punished (conflict), but not unpunished responding. BCCE (0.5–10 μg ICV) produced a dose-dependent reduction in the anticonflict activity of CDP. This was also significantly reduced by Ro 15-1788 (25 mg/kg IP) and a high dose of ACTH(4–10) (5 μg ICV). None of these test compounds had a marked direct effect on punished or unpunished responding in the doses used. These experiments provide further physiological support for the suggestion from binding studies that BCCE and Ro 15-1788 act on benzodiazepine receptors. However, the ability of ACTH(4–10) to reduce the anticonflict effect of CDP may be by some other, possibly opioid, mechanism.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00428161
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  • 36
    Digitale Medien
    Digitale Medien
    Benzodiazepine antagonist Ro 15-1788: Neurological and behavioral effects (1982)
    Springer
    Psychopharmacology 78 (1982), S. 8-18 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Benzodiazepines ; Benzodiazepine antagonist ; Ro 15-1788 ; Barbiturates ; Depressants ; Competitive antagonism ; Mouse ; Rat ; Dog ; Squirrel monkey
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In neurological and behavioral studies in mice, rats, dogs and squirrel monkeys, the imidazobenzodiazepinone Ro 15-1788 acted as a potent benzodiazepine antagonist. The antagonistic activity was both preventive and curative and seen at doses at which no intrinsic effects were detected. It was highly selective in that it acted against CNS effects induced by benzodiazepines but not against those produced by other depressants, such as phenobarbitone, meprobamate, ethanol, and valproate. The onset of action was rapid even after oral administration. Depending on the animal species studied, the antagonistic effects lasted from a few hours to 1 day. The acute and subacute toxicity of Ro 15-1788 was found to be very low. Benzodiazepine-like effects were not seen.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00470579
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  • 37
    Digitale Medien
    Digitale Medien
    A quantitative study in the rat on the relationship between imipramine levels in brain and serum (1982)
    Springer
    Psychopharmacology 76 (1982), S. 48-51 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Imipramine ; Serum levels of IMI ; Brain levels of IMI ; Tricyclic antidepressants ; Compartmentation of IMI ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Serum and brain levels of the tricyclic antidepressant drug imipramine (IMI) were studied in the rat under a variety of conditions. IV doses (range 1 nmol kg-1 to 15 μmol kg-1, 350 ng–5mg kg-1) and administered 5 min before death, were linearly correlated with IMI levels in serum, frontal cortex, and cerebellum. In this experiment, the highest levels of IMI were achieved in the frontal and occipital cortex and the lowest levels were found in the brain stem. The regional distribution was more even in rats pretreated with thiopental or γ-hydroxybutyric acid, drugs that alter cerebral blood flow. After 20 min or more, tracer amounts of IMI injected IV to IMI-pretreated rats [1 or 17 days, daily dose 2×36 μmol kg-1 (10 mg kg-1), last dose 89 μmol kg-1 (25 mg kg-1), 2–3 h before death] exhibited a distribution pattern in serum and various brain regions similar to that of the unlabeled drug. In the latter experiments, content (per volume) of the tracer or unlabeled IMI was more than 25-fold higher in various brain areas than in serum. It is concluded that despite large differences in drug levels in serum or brain, a close relationship is maintained under the conditions studied.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00430754
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  • 38
    Digitale Medien
    Digitale Medien
    THIP inhibits feeding behavior in fasted rats (1982)
    Springer
    Psychopharmacology 76 (1982), S. 75-78 
    Details
    ISSN: 1432-2072
    Schlagwort(e): THIP ; GABA ; d-Amphetamine ; Feeding behavior ; Anorexigenic agents ; GABA-receptor ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The effects of 4,5,6,7-tetrahydroisoxazolo-[5,4-c]pyridin-3-ol (THIP) were compared with those of d-amphetamine and GABA in fasted rats. Intravenously-administered THIP produced a dose-dependent decrease in food consumption (ED50≃1.5 mg/kg) by an action that was not reversed by prior subcutaneous or simultaneous intravenous (IV) injection of bicuculline. d-Amphetamine-SO4 also produced a decrease in food consumption in this model (ED50≃0.2 mg/kg, IV). Unlike THIP, GABA (in doses up to 100 mg/kg, IV) did not produce a marked anorexigenic effect. These results provide further evidence that THIP can penetrate the “blood-brain barrier”, and that central GABA-ergic systems are involved in controlling food intake.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00430760
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  • 39
    Digitale Medien
    Digitale Medien
    The role of fentanyl training dose and of the alternative stimulus condition in drug generalization (1982)
    Springer
    Psychopharmacology 76 (1982), S. 149-156 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Drug discrimination ; Drug generalization ; Fentanyl ; Morphine ; Amphetamine ; Nicotine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Different groups of rats were trained to discriminate fentanyl (F) (0.03, 0.02, or 0.01 mg/kg) from saline or to discriminate 0.03 mg/kg fentanyl (F) from alternative stimulus conditions (saline, 0.15 mg/kg nicotine, or 0.01 mg/kg F). When percentage of responses on the drug lever and percentage of time spent responding on the drug lever were used as dependent variables, it was found that training dose and alternative stimulus condition both affected the ED50 and the slope of the F generalization gradient. ED50 and slope values based on group data were not significantly different from values based on individual data. Differences between the results of the first and second 2.5-min period of the extinction test were not significant. ED50 and slope values were unaffected by the preceding training session, except in the group trained to discriminate 0.03 from 0.01 mg/kg F. A lever selection measure showed a significant effect of alternative stimulus condition on ED50 values only. Training dose and alternative stimulus condition also affected the generalization to morphine. Under none of the conditions explored in this study did generalization occur to amphetamine or nicotine. The results are discussed in terms of the relative nature of drug generalization.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00435269
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  • 40
    Digitale Medien
    Digitale Medien
    Differences in the effects of d-fenfluramine and morphine on various responses of rats to painful stimuli (1982)
    Springer
    Psychopharmacology 76 (1982), S. 188-192 
    Details
    ISSN: 1432-2072
    Schlagwort(e): d-Fenfluramine ; Morphine ; Brain serotonin ; Nociception ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The effects of d-fenfluramine and morphine on various nociceptive responses of rats were investigated. Unlike morphine, which inhibited all the responses examined, d-fenfluramine inhibited jumping and paw licking of rats on a hot plate, but did not increase the latency of tail withdrawal from hot water. The effects of d-fenfluramine on both responses on the hot plate were prevented by pretreatment with metergoline, a serotonin antagonist, whereas this pretreatment only reduced the effect of morphine on paw licking. The inhibition of tail withdrawal by morphine was also significantly reduced by metergoline treatment. The results confirm previous findings suggesting a role of serotonin in the mechanism by which morphine inhibits some nociceptive responses in rats. They also show that d-fenfluramine, a selective releaser and uptake inhibitor of serotonin at nerve endings, does not completely reproduce the antinociceptive effects of morphine in this species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00435276
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  • 41
    Digitale Medien
    Digitale Medien
    Increased food intake following the manipulation of intracerebral dopamine levels with gamma-hydroxybutyrate (1982)
    Springer
    Psychopharmacology 76 (1982), S. 273-277 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Gamma-hydroxybutyric acid ; Dopamine ; Stereotyped behaviour ; Food intake ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The administration of gamma-hydroxybutyric acid (GHB) initially causes a temporary “sleep-like” state during which there is an increase in forebrain dopamine levels. The present series of experiments examined whether in the period following the GHB-induced behavioural depression, when accumulated dopamine is dispersed, there is any behavioural evidence of increased dopaminergic activity. The first experiment, in which GHB was injected directly into the cerebral ventricles, demonstrated that in the immediate post-recovery period rats exhibited various forms of stereotyped oral behaviour and stereotyped sniffing. Unexpectedly, it was also observed that if food were present animals preferred to eat. The nature of this feeding response was examined in two further experiments. Firstly, it was shown that in the period following the behavioural depression animals would perform, in a dose-dependent fashion, an operant response which was rewarded by food. Secondly, the GHB-induced increase in feeding was abolished by the pre-treatment of animals with either the dopamine synthesis inhibitor alpha-methyl-p-tyrosine, or the dopamine receptor blocker haloperidol. These data indicate that (i) in the period when it is known that the GHB-induced accumulation of dopamine is dispersing, there is behavioural evidence of increased dopaminergic activity; (ii) the feeding response is not a simple oral reflex; and (iii) in addition to being essential for food intake dopaminergic transmission may play a direct role in the production of feeding.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432560
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  • 42
    Digitale Medien
    Digitale Medien
    DSP4-induced two-way active avoidance impairment in rats: Involvement of central and not peripheral noradrenaline depletion (1982)
    Springer
    Psychopharmacology 76 (1982), S. 303-309 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Systemic DSP4 ; Two-way avoidance ; Acquisition ; Spontaneous activity ; NA uptake ; Endogenous NA ; Peripheral NA ; Pain sensitivity ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract N-2-chloroethyl-N-ethyl-2-bromobenzylamine (DSP4) (50 mg/kg IP), a new selective noradrenaline (NA) neurotoxin, was found to cause a severe impairment of the acquisition of a two-way active avoidance task 1 week following adminsitration, an effect that was blocked by the selective NA uptake inhibitor desipramine. In a second experiment, systemically injected 6-OHDA (2×30 mg/kg IP) was not found to cause any avoidance impairment, althogh its effects upon peripheral NA were still evident 21 days after administration: The peripheral NA depletion caused by DSP4 almost disappeared 14 days after injection. In a third experiment, the avoidance impairment induced by DSP4 was produced even 10 weeks after treatment. Data from both the shuttlebox experiment and an activity box experiment suggest that the acquisition impairment is not readily explained on the basis of some deficit in spontaneous behavior or an altered perception of pain. The present data suggest that the effect of DSP4 upon active avoidance asquisition is mediated via central, and not peripheral NA neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00449115
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  • 43
    Digitale Medien
    Digitale Medien
    Effects of antimuscarinic cholinergic drugs injected systemically or into the hippocampo-entorhinal area upon passive avoidance learning in young rats (1982)
    Springer
    Psychopharmacology 76 (1982), S. 351-358 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Atropine ; Scopolamine ; Cholinergic mechanisms ; Hippocampal complex ; Learning ; Memory ; Passive avoidance ; Ontogeny ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Passive avoidance learning was significantly impaired by atropine (5 mg/kg, IP) or scopolamine (0.5 mg/kg), but not by methyl-atropine (5 mg/kg) or methyl-scopolamine (0.5 mg/kg), from postnatal day 15 on. In contrast, an improvement was observed, not significant at 11 days and significant at 13 days, probably due to nonspecific effects. Retention of the response increased from 6 h at 13 days, to 24 h at 17 days. In treated rats, retention was abolished at 13 and 15 days, and impaired at 17 and 20 days. Acquisition of the response was also significantly impaired by bilateral injections of atropine (1, 5, and 20 μg) into the posteroventral hippocampo-entorhinal (VHE) area, from day 15 on. Concomitantly, extinction was accelerated. At 14 days, atropine had no influence. At 13 days, a facilitatory action was observed, with better acquisition and greater resistance to extinction, possibly linked to affective changes. The results conform that central muscarinic cholinergic mechanisms are involved in passive avoidance learning from postnatal day 15 on, and demonstrate that some pathways of this system are located in the VHE area, become efficient at 15 days, and improve markedly between 17 and 18 days.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00449124
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  • 44
    Digitale Medien
    Digitale Medien
    Oral behaviour induced by intranigral muscimol is unaffected by haloperidol but abolished by large lesions of superior colliculus (1982)
    Springer
    Psychopharmacology 77 (1982), S. 272-278 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Substantia nigra ; Muscimol ; Oral stereotypy ; Haloperidol ; Collicular lesions ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract It has been suggested that the GABAergic striatonigral projection may form part of the efferent pathway responsible for the expression of dopamine-related oral behaviour. Consistent with this suggestion are reports that bilateral injection of the GABA agonist muscimol can produce stereotyped gnawing and biting. We report here two experiments on this effect: (1) A dose of the dopamine receptor blocker haloperidol (0.4 mg/kg), which effectively antagonised oral stereotypy induced by systemically administered apomorphine or intranigral carbachol, had no effect on either the latency or the intensity of the gnawing produced by intranigral muscimol (1 mM); (2) large lesions involving the superior colliculus which effectively suppressed the oral stereotypy induced by 8mg/kg apomorphine completely abolished the gnawing induced by intranigral injection of muscimol. Collicular lesions suppressed both the gnawing which occurred spontaneously and that elicited by a perioral probe. These findings are consistent with the view that the substantia nigra is a relay station between the caudate nucleus and the superior colliculus in an efferent pathway mediating dopamine-related oral behaviour. In addition, they raise the possibility that such behaviour is produced by the sensitisation of a collicular-mediated perioral reflex.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00464579
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  • 45
    Digitale Medien
    Digitale Medien
    Characteristic behavioral alterations in rats induced by rolipram and other selective adenosine cyclic 3′,5′-monophosphate phosphodiesterase inhibitors (1982)
    Springer
    Psychopharmacology 77 (1982), S. 309-316 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Rolipram ; Phosphodiesterase inhibitors ; Cyclic nucleotides ; Locomotor activity ; Rectal temperature ; Forepaw shaking ; Grooming ; Head twitches ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The significance of a characteristic symptomatology (hypothermia, hypoactivity, forepaw shaking, grooming, head twitches) as a potential in vivo correlate of enhanced availability of brain adenosine cyclic 3′,5′-monophosphate (cAMP) was examined in rats following systemic administration of various doses of dibutyryladenosine cAMP (dBcAMP) or of the phosphodiesterase (PDE) inhibitors rolipram, Ro 20-1724, ICI 63-197, isobutylmethylxanthine (IBMX), theophylline, cartazolate, and papaverine. The various PDE inhibitors could be assigned to three groups according to the pattern of behavioral alterations they induced. Rolipram, Ro 20-1724, and ICI 63-197 (group 1) caused hypothermia, hypoactivity, forepaw shaking, grooming, and head twitches. All behavioral effects were mimicked by dBcAMP but not dBcGMP. The order of potency and effective dosage range to induce the behavioral alterations were, in descending order, rolipram (0.09–1453 μmol/kg IP), ICI 63-197 (0.48–119 μmol/kg IP), Ro 20-1724 (5.6-1438 μmol/kg IP), corresponding with the recently reported efficacy of the drugs to elevate rat brain cAMP in vivo. Comparatively high doses of the alkylxanthine PDE inhibitors IBMX and theophylline (group 2) caused hypothermia, forepaw shaking, grooming, and head twitches concomitantly with a decline of the motor stimulatory effect, suggesting enhanced availability of brain cAMP. The order of potency and the effective dosage range to induce the behavioral alterations were, in descending order, IBMX (28.1–113 μmol/kg IP) and theophylline (139–555 μmol/kg IP). The third group, papaverine (295–1179 μmol/kg IP) and cartazolate (21.5–345 μmol/kg IP), caused only hypothermia and hypoactivity. The differences in the behavioral pattern of the two latter groups of compounds in comparison with dBcAMP and the selective cAMP PDE inhibitors are discussed with regard to their additional interference with adenosine actions besides their nonselective PDE inhibitory action.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432761
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  • 46
    Digitale Medien
    Digitale Medien
    Up- and down-regulation of central postsynaptic α2 receptors reflected in the growth hormone response to clonidine in reserpine-pretreated rats (1982)
    Springer
    Psychopharmacology 77 (1982), S. 327-331 
    Details
    ISSN: 1432-2072
    Schlagwort(e): α2 Receptors ; Noradrenergic receptors ; Receptor sensitivity ; Yohimbine ; Clonidine ; Tricyclic antidepressant ; Imipramine ; Growth hormone ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The α-adrenergic mechanisms exert a stimulatory influence on the secretion of growth hormone (GH) in the rat. In the present study the α receptors involved in GH regulation were characterized with respect to subtype. It was also investigated whether the GH response to α receptor agonists can be utilized to assess changes in the responsiveness of central α receptors. The experiments were performed on rats with implanted intra-aortic cannulae allowing frequent blood sampling from freely moving animals. Plasma GH was determined by radioimmunoassay. Reserpine (10 mg/kg) caused a suppression of the normal pulsatile secretory pattern of GH. The α receptor agonist clonidine (CLON) given to reserpine-pretreated animals induced a dose-dependent increase in plasma GH. The effect of CLON (0.2 mg/kg) was prevented by pretreatment with the α2 receptor antagonist yohimbine (3 mg/kg), but not by the α1 receptor antagonist phenoxybenzamine (10 mg/kg). Chronic pretreatment with CLON or imipramine, either of which can be expected to produce a reduced sensitivity of central α2 receptors, resulted in reduced GH responses to CLON. On the other hand, chronic treatment with yohimbine, which should cause denervation supersensitivity of α2 receptors, led to enhanced GH responses to CLON. The results indicate that GH release in the rat is stimulated by postsynaptic α2 receptors. They also suggest that the GH response to CLON can be used as a valid in vivo model reflecting decreased, as well as increased responsiveness of this type of receptor.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432764
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  • 47
    Digitale Medien
    Digitale Medien
    Lithium effects on rat brain glucose metabolism in vivo. Effects after administration of lithium by various routes (1982)
    Springer
    Psychopharmacology 77 (1982), S. 348-355 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Brain ; Lithium ; Drug-levels ; Glucose ; Glycolysis ; Krebs cycle ; Metabolism ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The effects of lithium on several brain energy metabolites were investigated in rats. Lithium was administered by three alternative routes: 1) in food, 2) via IP injection, or 3) intracisternally via the suboccipital route. Lithium given in food induced permanent changes, mainly in glycolytic processes and in glycogen content. Lithium injected IP induced, in addition, several changes which depended on the increase in brain lithium concentration following injection of lithium. These changes in brain metabolites disappeared as brain lithium concentration stabilized. Intracisternal injection of lithium produced brain lithium concentrations between 1 and 2 mmoles/kg wet wt., with a mean of about 1.6 mmoles/kg wet wt. Lithium concentrations below about 1.6 mmoles/kg wet wt. induced changes in brain metabolites which were similar to the changes seen after IP injection of lithium. Lithium concentrations above about 1.6 mmoles/kg wet wt. induced changes in several brain metabolites which were at variance with the changes induced by lower lithium concentrations. These changes were in many respects similar to changes in brain metabolites seen in rats exposed to convulsive treatment. It is hypothesized that such metabolic changes during lithium treatment, in discrete areas of the brain with higher concentration of lithium, e.g., hypothalamus, might be related to the prophylactic effect of lithium treatment in man.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432769
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  • 48
    Digitale Medien
    Digitale Medien
    The effect of d-amphetamine and amitriptyline administered to pregnant rats on the locomotor activity and neurotransmitters of the offspring (1982)
    Springer
    Psychopharmacology 77 (1982), S. 371-375 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Neural development ; Brain amines ; Prenatal administration ; Amitriptyline ; Amphetamine ; Locomotor activity ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract d-Amphetamine and amitriptyline (AT) were administered daily to female rats from day 7 of pregnancy until birth of the litters. Changes in the concentration of the biogenic amines, some of their metabolites, GABA, and the activities of glutamate decarboxylase, acetylcholinesterase (AChE), and choline acetyltransferase were determined in the whole brain of the offspring. The offspring of the amphetamine-treated rats showed a marked increase in serotonin concentration and that of its metabolite on postnatal day 1. Changes in the concentration of GABA were apparent on days 15 and 21 and were inversely correlated with changes in the activity of the synthesizing enzyme: Choline acetyltransferase and AChE activities were also increased at this time. Changes in neurotransmitter metabolism were not so evident in the offspring of rats treated with AT. The locomotor activity of the 8-, 15-, and 21-day offspring was also assessed. The offspring of the amphetamine-treated rats showed enhanced locomotor activity initially, but the activity decreased relative to the age-matched controls in the 21-day group. Offspring from the AT-treated group showed reduced locomotor activity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432773
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  • 49
    Digitale Medien
    Digitale Medien
    Discriminative stimulus properties of narcotic and non-narcotic drugs in rats trained to discriminate opiate ϰ-receptor agonists (1982)
    Springer
    Psychopharmacology 78 (1982), S. 63-66 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Drug discrimination ; Ethylketocyclazocine ; Bremazocine ; Nalorphine ; Pentazocine ; Buprenorphine ; Etorphine ; Dextrorphan ; Phencyclidine ; Ketamine ; Haloperidol ; Diazepam ; Pentobarbital ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The purpose of this study was to evaluate the discriminative stimulus properties of some narcotic and nonnarcotic drugs in rats trained to discriminate the effect of the proposed opiate ϰ-receptor agonists ethylketocyclazocine and bremazocine. Male Sprague-Dawley rats were trained in a two-lever food-reinforced paradigm to discriminate between the effect of ethylketocyclazocine (0.32 mg/kg) or bremazocine (0.04 mg/kg) and saline. Both groups of trained rats showed dose-dependent generalization to the effect of the proposed ϰ-agonist MRZ-2033 and some animals generalized the effect of nalophine and pentazocine. Some ethylketocyclazocine — but no bremazocine — trained rats generalized the effect of buprenorphine. The effect of dextrorphan, phencyclidine, and ketamine was generalized by some bremazocine-, but no ethylketocyclazocine-trained rats. Neither group of rats generalized the effect of etorphine, haloperidol, diazepam, or pentobarbital. These data suggest the usefulness of this procedure to evaluate the ϰ-like properties of opioid drugs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00470590
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  • 50
    Digitale Medien
    Digitale Medien
    Lithium does not prevent ECS-induced decreases in β-adrenergic receptors (1982)
    Springer
    Psychopharmacology 78 (1982), S. 190-191 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Electroconvulsive shock ; β-Adrenergic receptors ; Lithium ; Chronic treatment ; Depression ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Electroconvulsive shock (ECS) reduces the number of rat cortical β-adrenergic receptors. Lithium has been reported in several systems to prevent receptor changes induced by other agents. However, the present experiment reports that chronic lithium does not prevent the reduction in dihydroalprenolol binding induced by ten daily ECS treatments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00432261
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  • 51
    Digitale Medien
    Digitale Medien
    Radial maze as a tool for assessing the effect of drugs on the working memory of rats (1982)
    Springer
    Psychopharmacology 77 (1982), S. 268-271 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Radial maze ; Working memory ; Physostigmine ; Amphetamine ; Scopolamine ; Apomorphine ; Piracetam ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The effect of physostigmine (0.2 mg/kg), scopolamine (0.1 mg/kg), d,l-amphetamine (1 mg/kg), apomorphine (0.05 mg/kg), and piracetam (100 mg/kg) on working memory was examined in 12 rats that were highly overtrained in the radial maze. In experiment 1, drugs administered 10 min before the trial did not worsen performance of rats in the 12-arm maze. In experiment 2, insertion of a 5-min delay between the sixth and seventh choices increased the number of errors over choices 7–12. Performance was unaffected by pretreatment with physostigmine or apomorphine, but was significantly impaired by scopolamine, amphetamine, and piracetam. In experiment 3, performed in a 24-arm maze, the number of errors and trial duration increased, but performance was not decreased by amphetamine or piracetam. It is concluded that the uninterrupted radial maze task is relatively resistant to pharmacological disruption, but that scopolamine, amphetamine, and piracetam enhance the effect of stimuli interfering with the storage of spatial information over delays.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00464578
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  • 52
    Digitale Medien
    Digitale Medien
    Development and loss of tolerance to morphine in the rat (1982)
    Springer
    Psychopharmacology 78 (1982), S. 234-238 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Morphine ; Tolerance ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The development of a differential tolerance to morphine was investigated with respect to the mean effective dose, the threshold dose of tolerance, the degree of tolerance after a fixed dose, and the speed of tolerance loss. The mean effective doses, the threshold doses of tolerance, and the degree of tolerance differed considerably from effect to effect, whereas in all tests tolerance loss remained the same. The mean effective doses were not correlated to threshold doses of tolerance, degree of tolerance, or to the loss of tolerance, but a strong correlation exists between threshold doses of tolerance and degree of tolerance to all effects measured. Consequences of these results upon current theories of tolerance are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00428157
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  • 53
    Digitale Medien
    Digitale Medien
    The haematological and cardiac patterns of adaptation of rabbits to 4,500 m simulated altitude and of readaptation to 400 m (1982)
    Springer
    Research in experimental medicine 181 (1982), S. 197-204 
    Details
    ISSN: 1433-8580
    Schlagwort(e): Simulated altitude, adaptation ; Hypoxia ; Normoxia ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The haemoglobin (Hb), red blood cell count (RBC) and haematocrit (Hct) of 11 male rabbits were measured at weekly intervals during a 5-week exposure period to hypobaric hypoxia (simulated altitude, 4,500 m) and the following 4 weeks after restoring normoxic conditions in a climatic chamber at constant temperature. RBC showed the slowest response, Hct the fastest during adaptation to hypoxia and readaptation to normoxia. The body weight decreased during the 1st week at hypoxia and remained at a reduced level for 2 weeks after the return to normoxia. In female rabbits exposed up to 43 days to hypoxia the heart ventricle quotient (HVQ) (weights of left ventricle + septum/right ventricle) was determined. There was a gradual decrease of HVQ expressing the development of right heart hypertrophy which was not stabilised within the observation period.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01851190
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  • 54
    Digitale Medien
    Digitale Medien
    The effect of orally administered cadmium on the ultrastructure of the rat prostate (1982)
    Springer
    Urological research 10 (1982), S. 123-130 
    Details
    ISSN: 1434-0879
    Schlagwort(e): Prostate ; Cadmium ; Ultrastructure ; Testosterone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effects of cadmium and nickel chloride, administered in drinking water at 5 and 50 ppm, on the rat prostate are described. Zinc concentrations in the two lobes of the gland were unaffected by the metals and no consistent changes were observed at the subcellular level by X-ray microanalysis. The ultrastructural appearance of the prostate gland in rats of varying ages was unaltered following cadmium administration at those levels, while plasma testosterone concentrations did not differ significantly in cadmium treated animals. Low levels of cadmium (5 ppm) were accumulated by the ventral lobe of the prostate, although the metal was not detectable subcellularly. The results are discussed in relation to human prostatic carcinoma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00255954
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  • 55
    Digitale Medien
    Digitale Medien
    The central projections of visceral primary afferent neurons of the inferior mesenteric plexus and hypogastric nerve and the location of the related sensory and preganglionic sympathetic cell bodies in the rat (1982)
    Springer
    Anatomy and embryology 164 (1982), S. 413-425 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Visceral afferents ; Hypogastric nerve ; Preganglionic sympathetic neurons ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The central projections of visceral primary afferents of the inferior mesenteric plexus and hypogastric nerve of the rat were investigated using the transganglionic transport of horseradish peroxidase (HRP). In addition, the location of the corresponding spinal ganglion cells as well as the preganglionic sympathetic neurons is demonstrated. Labelled afferent axons were found in dorsal roots, dorsal root entry zone (preferentially in its lateral part), in all parts of the tract of Lissauer, and in the dorsolateral funiculus. Preterminal axons and/or terminals were distributed mainly to laminae I, IIa and the nucleus of the dorsolateral funiculus. Fewer afferents reached laminae IIb, III–V and X. Afferent projections are densest at L1 and 2 and the caudal T13, but extend up to T10 rostrally, and at least down to L4 caudally. A few visceral afferents ascend to the nucleus gracilis. The great majority of sensory and preganglionic sympathetic cell bodies is located at levels L1 and 2 bilaterally. A few cells are found in decreasing numbers rostrally up to T11. Preganglionic sympathetic neurons (PSN) are located in nucleus intermediolateralis (IML), n. intercalatus (IC) and n. commissuralis dorsalis (DCN). Axons of DCN and IC neurons run laterally, joining those of IML neurons on their way to the ventral roots. Dendrites of IML neurons ramify in all directions but preferentially to the dorsal horn and dorsolateral funiculus. Dendrites of IC and DCN neurons are distributed mainly mediolaterally, the latter also ventrally around the canalis centralis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315762
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  • 56
    Digitale Medien
    Digitale Medien
    Electron microscope observations on preimplantation mouse embryos cultured with LiCl (1982)
    Springer
    Anatomy and embryology 164 (1982), S. 343-347 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Preimplantation embryos ; Ultrastructure ; Effect of Li+
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We have recently shown that LiCl in the culture medium retards cleavage of mouse preimplantation embryos without delaying their blastulation and causes the formation of blastocysts with few large cells and a reduced or absent inner cell mass (Izquierdo and Becker 1982). In this study we compare the ultrastructure of major cellular organelles of Li+-treated and control embryos. No subcellular alterations were found that correlate with the altered morphology of the blastocysts. On the basis of these results we submit that the malformation of blastocysts developed in a Li+-containing medium is the morphogenetic consequence of a retardation of cleavage coupled with a normal timing in the establishment of zonular tight junctions around the peripheral cells of the morula.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315756
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  • 57
    Digitale Medien
    Digitale Medien
    Scanning electron microscopy of prenatal muscle development in the mouse (1982)
    Springer
    Anatomy and embryology 164 (1982), S. 379-385 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Muscle ; Growth and Development ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Scanning electron microscopy was used to study prenatal muscle development in mouse fetuses ranging from 12 days to 18 days gestation. Some transmission electron micrographs were also used for comparison. At 12 days no myofibres were evident although at 13 days long fibres surrounded by many mononucleated cells could be seen. At 14 days bundles of primary myofibres were observed with new myofibres forming in crevices between adjacent fibres. At 16 days the primary myofibres had separated but smaller secondary myofibres could be seen forming along their surfaces. The myofibres were very compact at 18 days and often appeared fused but this was due to the basal lamina ensheathing clusters of primary myofibres with their secondaries. The scanning electron micrographs appeared to illustrate the theories of muscle development which have arisen out of the various studies employing sectioning techniques.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315759
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  • 58
    Digitale Medien
    Digitale Medien
    Immunohistochemical and electron microscopical studies of mitotic adenohypophysial cells in different ages of rats (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 51-61 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Anterior pituitary cells ; Mitosis ; Rat ; Immunohistochemistry ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Mitotic rates of the six types of immunohistochemically identifiable adenohypophysial cells were histometrically calculated in colchicine-pretrated male rats 5, 17, 30 and 70 days old. Sections were stained with the antisera against rLH, rFSH, rTSH, oGH, rPRL and pACTH1–39. The mitotic growth rate of the anterior pituitary gland at 30 days of age was much higher than at other times. Mitotic growth rates of GH and PRL cells increased with advancing age, while those of ACTH-, TSH- and immunonegative cells decreased with advancing age. LH/FSH cells showed no variation in mitotic growth rate with age. Mitotic cells can be classified into six cell types based on their fine structural properties: (1) agranular cells associated with the folliculo-stellate cells; (2) ambiguous cells with scanty minute secretory granules (50–150 nm in diameter); (3) basophils with a number of small secretory granules (130–200 nm); (4) immature acidophils whose large secretory granules (130–300 nm) are sporadically scattered; (5) acidophils with numerous spherical larger secretory granules (200–300 nm); and (6) prolactin cells with large polymorphic granules. At day 5 there was a high mitotic rate of the agranular and ambiguous cells [types (1) and (2)]; at day 70 a high mitotic rate was found in immature and mature acidophils [types (4) and (5)]. The mitotic rate of basophils (type 3) was high only at day 17 and low at all other times. The mitotic rate of prolactin cells (type 6) showed a slight increment with advancing age. It is concluded that the mitotic rates of the six cell types are age-dependent.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00304582
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  • 59
    Digitale Medien
    Digitale Medien
    Morphogenesis and histogenesis of the connecting tubule in the rat kidney (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 81-95 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Kidney ; Connecting tubule ; Differentiation ; Growth and development ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary At the start of its morphogenesis the tubule of an S-shaped body always attaches to the terminal ampulla of the collecting duct. It remains attached there for some time while the terminal ampulla sprouts toward the renal capsule. The most distal part of the tubule that rises to the ampulla forms the connecting tubule, morphogenically the oldest segment of the tubulus nephroni. When younger S-shaped bodies join the same terminal ampulla, 2 to 3 connecting tubules are temporarily attached side by side to a single ampulla. Soon, however, the connecting tubule of the older nephron shifts its point of attachment away from the ampulla to the connecting tubule of the younger nephron. This process is repeated through successive nephron generations. Thus an arcade develops which at the close of morphogenesis includes the connecting tubules of the 3 to 4 oldest juxtamedullary and midcortical nephrons of the collecting duct and is always situated close to interlobular veins. The connecting tubules of the 2 youngest subcapsular nephrons are not incorporated into arcades, but join directly and permanently the collecting duct. — At the start of histogenesis, the undifferentiated tubule epithelium of the S-shaped body has a uniform structure over its entire length. At the junction of the connecting tubule and the terminal ampulla there is a cytologically sharp boundary between cuboidal, dark-stained connecting-tubule epithelium of the nephron and cylindrical, light-stained ampullary epithelium of the collecting duct. The epithelial differentiation begins in the oldest, juxtamedullary connecting tubules of an arcade and progresses upward to the terminal ampulla, so that immature connecting-tubule epithelium and immature ampullary epithelium are temporarily interposed between mature connecting-tubule epithelium and mature collecting-duct epithelium. The mature epithelium of the connecting tubule stains light, in which respect it behaves like the epithelium of the distal tubule. However, it also contains individual cells that are more strongly basophilic, stain dark and, though of nephrogenic origin, cannot be distinguished from the dark cells of the collecting duct by light microscopy. — Morphogenically and histogenically, the arcade-forming connecting tubules and the subcapsular connecting tubules arise from the nephrogenic blastema.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00304585
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  • 60
    Digitale Medien
    Digitale Medien
    Occurrence of preantral intra-ovarian oocyte release in the rat and the Syrian hamster (Mesocricetus auratus) (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 169-175 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Ovary ; Oocyte ; Follicles ; Rat ; Syrian Hamster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Serial sections of 62 rat ovaries and 66 ovaries from Syrian hamsters (Mesocricetus auratus) have been examined by light microscopy. The relative and absolute percentage of preantral intra-ovarian oocyte release (PIOR) was recorded. PIOR was incomplete when the rupture of the basal membrane was not followed by the release of the oocyte from its preantral follicle into the ovarian stroma; conversely, a PIOR was regarded to the complete if the oocyte was released from the preantral follicle into the adjacent stroma. PIOR occurred in 23% of rat ovaries and in 32% of hamster ovaries; meiosis was not resumed. In rat ovaries the frequency of complete PIOR was 71%; the oocyte disappeared quickly after its release and herniated granulosa cells could invade capillaries. By contrast, incomplete PIOR was prevalent in hamster ovaries (67%); oocytes survived in the interstitial cortical tissue after the disappearance of their granulosa and theca cells (“free oocytes”). It is concluded that PIOR reflects the onset of follicular atresia and that different local factors are probably responsible for species differences.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305475
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  • 61
    Digitale Medien
    Digitale Medien
    Formation of perichromatin granules, nematosomes and concentric lamellar bodies in sympathetic postganglionic perikarya in response to immobilization stress (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 281-290 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Ultrastructure ; Sympathetic neurons ; Immobilization ; Perichromatin granules ; Nematosomes ; Concentric lamellar bodies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Perichromatin granules, nematosomes (threadlike bodies), or concentric lamellar bodies were rarely observed in profiles of principal ganglionic neurons in the untreated rat superior cervical ganglion. They were more frequenlty encountered in these neurons following long-term activation of the sympathetic nervous system by intermittent immobilization (6 to 18 12-h periods). The increased number of the described nuclear and cytoplasmic structures following immobilization is documented by morphometric data and discussed in relation to specific chronic neuronal hyperactivity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305482
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  • 62
    Digitale Medien
    Digitale Medien
    The peripheral neuropathy in de Sanctis-Cacchione syndrome (1982)
    Springer
    Acta neuropathologica 56 (1982), S. 194-200 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Xeroderma pigmentosum ; de Sanctis-Cacchione syndrome ; Peripheral neuropathy ; Morphometry ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Histological, ultrastructural, and morphometric studies were performed on nerve and muscle biopsies from three patients with de Sanctis-Cacchione syndrome. Sural nerves showed marked loss of the myelinated fibers, in proportion to decrease in nerve conduction velocities and in inverse proportion to the severity of the clinical symptoms, which were related to the survival length. The larger fibers were involved earlier and more markedly than the smaller. The unmyelinated fibers were also decreased in number. Electron-microscopic studies showed the presence of primary degeneration of myelin sheaths or Schwann cells. Muscle biopsies showed grouping of type I and type II fibers in all three patients. Therefore, peripheral nerve involvement in de Sanctis-Cacchione syndrome was suggested to result from chronic degeneration of the neuronal cells and Schwann cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00690635
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  • 63
    Digitale Medien
    Digitale Medien
    Peripheral nerve fibre degeneration in protein-deprived young rats (1982)
    Springer
    Acta neuropathologica 57 (1982), S. 1-6 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Rat ; Malnutrition ; Protein deprivation ; Peripheral nervous system ; Ultrastructure ; Degeneration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In a previous study the occurrence of nerve fibre degeneration with a distribution as in dying-back neuropathies was described in young rats subjected to severe protein deprivation (Oldfors 1981). In this study the ultrastructural appearance of the degeneration of the nerve fibres at different levels of the longitudinal tail nerves in severely protein-deprived rats has been investigated. Various structural changes were noted, the most common being bands of Büngner indistinguishable from those seen in Wallerian degeneration. In nerve fibres which were less severely affected the most common finding was shrinkage of the axon with concomitant folding of the myelin sheath. Other structural changes included axonal accumulation of 10 nm filaments or mitochondria and other cell organelles, areas of demyelination, and projections of axolemma and Schwann cell membrane into the axon. Signs of axonal regeneration occurred but were infrequent. The degenerative changes seen at various levels of the nerves support the view that the neuropathy is of distal axonal type, but the structural appearance differs from several of the toxic dying-back neuropathies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688871
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  • 64
    Digitale Medien
    Digitale Medien
    Ultrastructural findings in so-called ependymal rat tumors induced by transplacental administration of ethylnitrosourea (ENU) (1982)
    Springer
    Acta neuropathologica 57 (1982), S. 51-58 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Ependymoma ; Rat ; Ethylnitrosourea ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Tumors of the central nervous system (CNS) in Sprague-Dawley and Lewis rats were induced transplacentally by a single intraperitoneal (IP) injection of 10–25 mg/kg ethylnitrosourea (ENU) on days 16–20 of gestation. Light-microscopic examination revealed that 22% of these tumors could be diagnosed as ependymomas, anaplastic ependymomas (ependymoblastomas), or mixed tumors revealing both oligodendroglioma and anaplastic ependymoma tissues if the criteria of accepted classifications were followed. Electron-microscopic examination, however, demonstrated that the ependymoma and the anaplastic ependymoma-like tissue in ENU-induced tumors lacked ependymal features, such as basal bodies, cilia, complicated junctional complexes, microvilli, etc. This tissue type was repetitious, always being composed of cells arranged in groups, cords, and rosette-like (pseudorosette) formations. In the pseudorosettes, the cell nuclei were polarized at the periphery and the cytoplasm contained numerous polyribosomes, occasional short microtubules and usually a few small dense-core vesicles. The center of the pseudorosettes showed numerous slender interdigitating processes interconnected by maculae adherens. The tips of these processes showed vesicular degeneration. The cells arranged in groups or cords and perivascular rosettes revealed identical ultrastructure, but they were not polarized. The present findings indicate that the socalled ENU-induced ependymomas and anaplastic ependymomas are not true ependymal tumors, but rather primitive neuroepithelial neoplasms with some features of oligodendroglioma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688877
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  • 65
    Digitale Medien
    Digitale Medien
    Distal symmetric polyneuropathy in the spontaneously diabetic BB-Wistar rat (1982)
    Springer
    Acta neuropathologica 58 (1982), S. 39-47 
    Details
    ISSN: 1432-0533
    Schlagwort(e): BB-Wistar rat ; Diabetic distal symmetric neuropathy ; Axonal degeneration ; Teased fibers ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The distal, symmetric polyneuropathy of the spontaneously diabetic BB-Wistar rat was studied ultrastructurally and by means of teased fiber preparations. Ultrastructural findings consisted of malorientation of the axonal cytoskeleton, followed by axonal atrophy, secondary myelin breakdown and distal Wallerian degeneration. This sequence of structural changes could be confirmed by scoring of pathological abnormalities and morphometric evaluation of teased fibers. Distal sensory nerve fibers were affected earlier and more severely than motor fibers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00692696
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  • 66
    Digitale Medien
    Digitale Medien
    Telencephalic cytoarchitectonics in the brains of rats with graded degrees of micrencephaly (1982)
    Springer
    Acta neuropathologica 58 (1982), S. 203-209 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Architectonic anomalies ; Rat ; Telencephalon ; Micrencephaly ; Methylazoxymethanol acetate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Graded degrees of micrencephaly were produced in the progeny of rats given 0, 14, 22, or 30 mg methylazoxymethanol acetate (MAM Ac) per Kg b.wt. on gestation day (GD) 15. Brains of animals from five litters were examined at each dose level. Golgi-Cox-stained sections prepared from brains of progeny of rats given 25 mg MAM Ac/kg on GD 15 were also evaluated for four micrencephalic and four control animals. Each increase in dosage of MAM Ac resulted in significantly greater loss in brain weight in the progeny. The largest effect was on the telencephalon. In the low dose group the telencephalon, though noticeably smaller, was structurally normal. The two higher doses resulted in easily visualized neuropathologic lesions in both the cerebral cortex and hippocampus. The external layers of the cerebral cortex were most severely affected. Layers V and VI were much better preserved but measurements on pyramidal cells in layer VI in the Golgi-Cox-stained sections showed them to have significantly fewer dendrites and spines than the normal animals. In addition to an intrinsic disorganization of the neocortex, periventricular nodular heterotopias and hippocampal ectopias were common. All the structural anomalies were most severe at the highest dose, though they were also readily apparent at the intermediate dose. The findings suggest to us that MAM Ac treatment during gestation not only produces an acute lesion resulting in the destruction of many proliferating neuroblasts, but that many of the surviving neuroblasts may sustain a chronic lesion altering their subsequent development.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00690802
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  • 67
    Digitale Medien
    Digitale Medien
    Experimental hematogenic metastases of malignant schwannoma in the rat (1982)
    Springer
    Acta neuropathologica 57 (1982), S. 151-157 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Experimental ; Hematogenic ; Metastases ; Schwannoma ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary To study development, growth patterns and morphology of metastatic schwannomas in an animal model, adult Lewis rats were injected intravenously with tissue culture cells derived from a malignant schwannoma induced in a female LEW/mai rat by transplacental administration of ethylnitrosourea (LNU). Groups of animals received a single injection of 0.1×105; 0.5×105; 1.0×105; 5.0×105; 10×105 or 100×105 cells via the femoral vein. The injections resulted in the development of metastatic tumors, primarily involving the lung in all animals. Lung metastases were observed in the form of microscopic and macroscopic peripheral subpleural tumors, central peribronchial and perivascular tumors, parenchymal tumors, diffuse intraalveolar infiltrates and intravascular tumor emboli which were growing. Animals receiving high dosages had a greater variety of forms of the metastatic growth in the lungs than those given low dosages. The animals which received the highest dose had the greatest degree of total lung tumor burden. In 36 of the 60 animals injected, metastatic tumors also developed in the pericardium. Thirteen animals developed metastatic tumors in the kidney, heart, ovary, adrenal, intestine or skeletal muscles. As the cell dosages were increased, more organs became involved, but no tumors developed in the brain.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00685383
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  • 68
    Digitale Medien
    Digitale Medien
    Effect of ovariectomy on longitudinal bone growth in the rat (1982)
    Springer
    Anatomy and embryology 164 (1982), S. 9-18 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Ovariectomy ; Growth ; Bone ; Rat ; Tetracycline
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The effect of ovariectomy on longitudinal bone growth was studied in growing rats. The operation was performed at ages 20, 40, and 60 days. Sham operations were made at age 40 days. At different postoperative intervals, the growth rate was determined with the tetracycline technique, and the width of the growth plate was registered. After a slight initial retardation, the growth rate after ovariectomy was significantly greater than in normal rats during a 40–60 day period. During the same period, the growth plate was wider. The increase in growth rate was greater and more rapid if ovariectomy was performed in older animals. The results indicate that ovariectomy increases longitudinal bone growth and that longitudinal bone growth and skeletal maturation depend less on ovarial function in young animals than that in more mature animals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00301875
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  • 69
    Digitale Medien
    Digitale Medien
    Catecholamine-containing neurons in the mesencephalic tegmentum of the chicken (1982)
    Springer
    Anatomy and embryology 164 (1982), S. 303-313 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Catecholamine ; Histofluorescence ; Ultrastructure ; Brain stem ; Chicken
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The nucleus tegmentalis dorsalis (NTD) which may be homologous with the mammalian locus coeruleus was investigated in the chicken by means of light, fluorescence and electron microscopy. Results are summarized as follows: 1) Numerous neurons emitting green fluorescence by the Falck-Hillarp method were observed in the NTD of the chicken. By consecutive light and fluorescence microscopy of the same section it was established that these catecholamine(CA)-containing neurons clearly coincided with the cell group named nucleus tegmentalis dorsalis by Jungherr (1945). This procedure further showed that there were also non-fluorescent neurons in the NTD. 2) On the basis of electron microscopic observation, two types of neurons were recognized in the NTD: medium-(15–25 μm) and small-sized (10–15 μm) neurons. Medium-sized neurons had a round to oval nucleus with several deep infoldings and abundant organelles. From combined fluorescence and electron microscopic examination, they obviously corresponded with CA-containing neurons demonstrated by the Falck-Hillarp method. Small-sized neurons had a round nucleus surrounded by pale cytoplasm. They corresponded with non-CA-containing neurons. 3) From morphometric analysis, it was clear that CA-containing neurons contained a well-developed rough-surfaced endoplasmic reticulum and many lysosome-like dense bodies, unlike non-CA-containing neurons. This study was undertaken as the basis of a research program to elucidate the catecholaminergic projections from the NTD.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315753
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  • 70
    Digitale Medien
    Digitale Medien
    Ontogenetic appearance of immunoreactive endocrine cells in rat pancreatic islets (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 63-70 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Pancreatic islet ; Cytogenesis ; Immunohistochemistry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Chronological development of immunoreactive, pancreatic endocrine cells was immunohistochemically studied in rats. The first immunoreaction occurs for glucagon on day 11.5 and for insulin on day 12.5 of gestation, respectively, in the cells located within the cap-like or tubular pancreatic primordium derived from the gut wall. Immunoreactive somatostatin cells appear first at the periphery of primitive islets on day 15.5. On day 18.5, the cells of the primitive islets obtain their definitive arrangement and the islets are now separated from the tissue of the exocrine pancreas. Decapitation or encephalectomy performed on day 16.5 embryos fails to influence the ensuing further development of endocrine pancreas. This suggests that the hypothalamus or pituitary does not play an essential role in the histogenesis of the pancreatic islets.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00304583
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  • 71
    Digitale Medien
    Digitale Medien
    Distribution patterns and individual variations of callosal connections in the albino rat (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 213-232 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Callosal connections ; Neocortex ; Columnar organization ; Rat ; Degeneration techniques
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary After complete callosotomy the distribution of degeneration products was re-investigated in adult albino rats. Three to seven days post operation, coronal, horizontal and “flattened” sections were impregnated according to the new methods of Gallyas et al. (1980) which stain degenerating axons and terminals, respectively. The regional distribution patterns of callosal terminals were directly visualized with dark field illumination at low magnification. With this technique the distribution pattern of axons and terminals could be compared between different cortical regions and individuals. Callosal terminals tend to accumulate in patches or bands along the borders of cortical regions and areas. The concentration of callosal terminals was especially high at the common corners of more than two cortical areas. The callosal system shows a rather constant distribution pattern which is composed of column shaped subunits. Considerable individual variations were recognized concerning the number, position, shape, density and contiguity of the columnar units either occupied by callosal connections or empty. Although the laminar distribution of callosal terminals shows some similarities in different areas of the cortex, there is no common laminar pattern characteristic either for the whole neocortex or for any cortical region. The comparison between consecutive sections stained either for degenerating fibers or degenerating axon terminals revealed that the callosal axons do not determine directly the arrangement and packing density of callosal synapses. Whatever determines the position and amount of callosal synapses this influence seems to be exerted via translation into the columnar organization.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305478
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  • 72
    Digitale Medien
    Digitale Medien
    Spinal projections to the lateral reticular nucleus in the rat (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 345-359 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Lateral reticular nucleus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The synaptic relationships and the distribution of the afferent terminals of the spinal pathway to the lateral reticular nucleus (LRN) of the rat were examined following induced degeneration. After high cervical hemisections, the spino-LRN projection was first examined with the Fink-Heimer silver impregnation method. Degeneration was confined primarily to the ipsilateral LRN and all three divisions of the nucleus were involved. Maximum degeneration was observed in the caudal regions of the parvocellular division. The magnocellular division, except for the extreme dorsomedial area, showed substantial degeneration as well. The subtrigeminal division throughout its entire length contained only sparse degeneration. Electron microscopic examination following spinal cord lesions revealed both round and pleomorphic-vesicle terminals in various stages of electron dense degeneration. The majority of the degenerating terminals were of the round-vesicle variety. Both types of terminals contacting somata were also observed to degenerate but their number was small in comparison to those on dendritic profiles. Terminals in synaptic contact with two dendritic profiles were also observed to degenerate. Some of the large terminals belonging to synaptic configurations (glomeruli) underwent degeneration and were therefore of spinal origin as well.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305572
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  • 73
    Digitale Medien
    Digitale Medien
    A Golgi study of the lateral reticular nucleus in the rat (1982)
    Springer
    Anatomy and embryology 164 (1982), S. 243-256 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Lateral reticular nucleus ; Golgi ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The organization of the lateral reticular nucleus (LRN) of the rat was investigated by using the Golgi technique. Golgi-Cox preparations revealed neurons with shapes similar to those observed in Nissl-stained preparations. Fusiform cells possess rectilinear dendrites with secondary dendrites which are longer than the parent stem. The remaining cell types have short dendrites which branch for three or four generations and follow a tortuous course. These two types of neurons are similar to the isodendritic and allodendritic neurons which have been reported in the reticular formation. The neurons throughout the LRN form cell clusters. In Golgi preparations five to ten cells are seen in each cluster but counterstaining reveals that the clusters are made up of many more cells than the Golgi preparations suggest. Many cells lie in close apposition and the dendrites of the cells in each cluster intertwine to form dendritic plexuses. Dendritic input from both neighbouring and distant cell clusters also contributes to the plexus formations within each cell cluster. Under high magnification, the dendrites show irregularities in their contours, including warty excrescenses, bumps and an array of spines, some of which are pedunculated. The appendages are confined primarily to distal portions of the dendrites, with few spines observed on the somata and proximal dendrites. Varicosed dendrites are also in common occurrence throughout the nucleus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00318508
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  • 74
    Digitale Medien
    Digitale Medien
    Histogenesis of the loop of Henle in the rat kidney (1982)
    Springer
    Anatomy and embryology 164 (1982), S. 315-330 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Kidney ; Loop of Henle ; Differentiation ; Growth and development ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The epithelial differentiation of the loop of Henle was investigated in the kidneys of Wistar rats between embryonic day 15 and postnatal day 30. Three stages can be distinguished in the development of the loop of Henle: (1) the primitive loop, (2) the immature loop and (3) the mature loop. The primitive loop of Henle is composed of thick undifferentiated tubule epithelium and is divided into a strongly basophilic proximal tubule anlage that stains dark in the semithin section, and a weakly basophilic, light-staining distal tubule anlage. The two anlages are separated by a cytologically sharp boundary located in the descending limb just before the bend of the loop. The immature loop of Henle is present when differentiation of the tubule epithelium begins. The shorter initial portion of the proximal tubule anlage develops into proximal straight tubule epithelium with brush border, brush border enzymes and lysosomal enzymes, while the longer, more distal portion of the proximal tubule anlage develops into thin undifferentiated epithelium that is a transitory feature of the immature loop stage. The primitive epithelium of the distal tubule anlage develops into distal straight tubule epithelium. The cytologically sharp boundary of the thin undifferentiated epithelium and distal tubule epithelium is located just before the bend of the loop. The loop of Henle matures as the thin undifferentiated epithelium in the medullary ray and outer stripe of the outer medulla becomes transformed into proximal straight tubule epithelium. At the point where this descending differentiation ends, the borderline of the inner and outer stripe of the outer medulla arises. The thin undifferentiated epithelium in the inner stripe and the inner medulla differentiates into the thin epithelium of the descending limb of Henle's loop. In the bend and ascending limb of long loops, the thick distal tubule epithelium is trans-formed by an ascending autophagous process into the thin epithelium of the ascending limb of Henle. The termination of this process marks the borderline between the inner and outer medulla. The thin descending and thin ascending limb of Henle arise from 2 different anlages; between them lies the histogenetic boundary of the proximal and distal renal tubule.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00315754
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  • 75
    Digitale Medien
    Digitale Medien
    Histogenesis of the inferior colliculus in rat (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 19-37 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Auditory system ; Inferior colliculus ; Cell migration ; Neuronal differentiation ; Radial glial fibers ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The early histogenesis of the inferior colliculus from embryonic day 11 to 18 (E11 to E18) has been studied in the rat by analysis of Golgi impregnated material and plastic sections. This analysis has shown that the pseudo-stratified columnar neuroepithelium observed at E11 is followed by the appearance at E12 of three zones: marginal, intermediate and ventricular. Signs of cell differentiation are first observed in the intermediate zone. Secondary rearrangements occur within this zone, and by E16 a thin cortical plate (the cortex of the inferior colliculus) develops at the junction of the intermediate and marginal zones giving rise to the external and pericentral nuclei of this structure, which has a cortical organization in adults. The remainder of the intermediate zone (the nucleus of the inferior colliculus), invaded by axons, expands dramatically by E16–E17 and gives rise to the central and dorso-medial nuclei of the inferior colliculus which have a nuclear organization in adults. The morphogenetic events which take place in these two regions differ and can be identified by the study of cell migration and differentiation. In the nucleus of the inferior colliculus, neuronal migration begins with detachment of the ventricularly directed process, or trailing process, of the primitive epithelial cell from the ventricular surface. This is followed by the ascent of the cell nucleus through the pially directed, or leading, process by a mechanism identical to the perikaryal translocation already described in other regions of the nervous system. This mechanism of cell migration is characteristic of a first type of migratory young neuron (type I). Axons initiate from the leading process of these cells during migration and dendrites grow out in various directions giving these cells a bipolar or a multipolar appearance. Dendritic differentiation occurs first in the outermost cells of the nucleus and proceeds inwards. In the cortex of the inferior colliculus, neuronal migration also begins with detachment of the ventricular process, which occurs by E12, immediately followed by the detachment and retraction of the apical or leading process. Within the intermediate zone, migratory cells become rounded and sprout numerous processes. One of these processes is tipped by a growth cone and displays all the characteristics of an axon. It is directed tangentially in the intermediate layer. Dendritic growth and differentiation starts when the cells reach their final position in the cortical plate, and proceeds from the innermost cells outward. Due to the inadequacy of our methods for identifying radial glial fibers, the mechanism of migration of this type of cell (type II) remains unclear. Our results confirm that the inferior colliculus of the rat is organized as a central nuclear mass surrounded by a thin cortex. As previously observed in other regions of the nervous system, the modes of cell migration and differentiation in the cortical and non-cortical structures of the inferior colliculus appear different.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00304580
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  • 76
    Digitale Medien
    Digitale Medien
    Anatomy of the guinea-pig cecum (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 97-111 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Cecum ; Guinea pig ; Anatomy ; Ultrastructure ; Bacteria (microvilli)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The anatomy of the cecum of the domesticated guinea pig (Cavia apera f. procellus) was investigated at the macroscopic and microscopic levels. In situ observations, injections of the blood vascular system and the preparation of dried specimens were made to elucidate the macroscopic anatomy of the cecum. The complex mesenterial situation in the abdomen was also investigated. The guinea-pig intestinal tract is particularized by the presence of the voluminous teniated cecum, which lacks an appendix vermiformis. The stomach is relative small and simple; the large intestine does not possess teniae. Seen with the scanning electron microscope the surface topography of the cecal wall shows a pattern of irregular mounds and crevasses. The former are made up of raised ridges, often in circular or looped profiles. Correlated light microscopic observation revealed an irregularity of the mucosal surface consisting of protrusions into the cecal lumen, the circular and looped configurations of the scanning microscope image representing the entry into crypts at the light-microscopic level. The close association of bacteria to the mucosal surface is striking. Observed with the transmission electron microscope this close association takes the form of an intermicrovillar location of the bacteria. The present observations are compared to those made on other rodents and with respect to the dietary habit of the guinea pig.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00304586
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  • 77
    Digitale Medien
    Digitale Medien
    Innervation pattern of inferior vena cava in mouse and rat (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 233-238 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Inferior vena cava ; Autonomic nervous system ; Adrenergic nerves ; Cholinergic nerves ; Mouse ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The innervation pattern of rat and mouse inferior vena cava was studied using catecholamine fluorescence and cholinesterase histochemical methods. Adrenergic nerve fibers innervate only abdominal protions of the inferior vena cava, while cholinergic nerves are chiefly distributed to the thoracic inferior vena cava and show a gradual decrease in the abdomen. Chemical sympathectomy performed with the neurotoxin 6-hydroxydopamine does not alter the pattern of cholinergic innervation of the inferior vena cava, suggesting the parasympathetic nature of cholinergic nerves.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305479
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  • 78
    Digitale Medien
    Digitale Medien
    An ultrastructural study of the lateral reticular nucleus in the rat (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 329-344 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Lateral reticular nucleus ; Ultrastructure ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A systematic study of the normal synaptic patterns within the lateral reticular nucleus (LRN) of the rat revealed various synaptic relationships. Two types of axon terminals were identified according to the morphology of the synaptic vesicles contained within them. Axon terminals with round vesicles established asymmetrical synaptic contacts with the somata and all areas of the dendritic trees including somatic and dendritic appendages. Pleomorphic-vesicle terminals established symmetrical synaptic contacts on somata and their appendages and on all sizes of dendrites and their appendages. Both round and pleomorphicvesicle terminals were infrequently seen to synapse upon the somata and proximal dendrites. The round-vesicle terminals outnumbered the pleomorphic-vesicle terminals on the dendritic trees. Terminals of the en passant type were also common throughout the LRN. Both round and pleomorphic-vesicle terminals were observed simultaneously contacting the soma and one or more dendritic profiles, or two different dendritic profiles. Synaptic configurations (glomeruli) were also observed in all three divisions of the nucleus. They consisted of a large, central, round-vesicle terminal contacting a number of small-calibre dendritic processes. This arrangement was surrounded by one or more sheets of glial lamellae. Puncta adherentia were observed on the apposed membranes of adjacent cells, adjacent dendrites and adjacent axon terminals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305571
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  • 79
    Digitale Medien
    Digitale Medien
    Ultrastructural study of seminiferous tubules in the rat after prenatal irradiation (1982)
    Springer
    Anatomy and embryology 165 (1982), S. 425-435 
    Details
    ISSN: 1432-0568
    Schlagwort(e): Sertoli cells ; Development ; Ultrastructure ; Prenatal irradiation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Is the presence of germinal cells necessary for the Sertoli cells to acquire normal features? To respond to this question we have studied the development of the Sertoli cells in rats irradiated at the end of the foetal life. In the prenatal irradiated rats, the lumen of the seminiferous tubules appears later than in the control rats. The Sertoli cells show numerous flexuous apical processes, with central microtubule bundles. These processes regress progressively after the 40th day of life when the tubular lumen appears; numerous junctional complexes differentiate with the same structure as those of control animals. There are important dilatations of the intercellular spaces. The cytoplasmic organelles show a normal development up to the 40th day of life. After this period, the rough endoplasmic reticulum and the Golgi apparatus clearly regress while important dilatations appear in the smooth endoplasmic reticulum and persist in the adult animal. From the 35th day on, the basal lamina of the seminiferous tubules is irregular and multilayered. The differentiation of the Sertoli cells seems to be independent of the presence of germinal cells until the 40th day of life and presents several particularities; thereafter the Sertoli cells show signs of regression.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00305578
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  • 80
    Digitale Medien
    Digitale Medien
    Light- and electron-microscopic features of an endocrinologically active pituitary adenoma cultured in vitro (1982)
    Springer
    Acta neuropathologica 56 (1982), S. 245-249 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Pituitary adenoma ; Cell culture ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A pituitary adenoma from an acromegalic female patient has been studied in cell cultures. Two populations of parenchymal cells, i.e., elongated shapes and big pale forms with irregular outlines, were distinguished light-microscopically. Ultrastructurally, three types of cells were found. Two of them contained secretory granules in varying numbers and sizes. Based on the proportion of the various cellular elements these cells were considered as counterparts of the elongated shapes being responsible for the GH secretion at different rates. The third cell type with very few secretory granules was identified with the big pale forms. Presumably, they could be exhausted GH-secreting cells. Besides fine structural characterisation, cultured cells of endocrinologically active human pituitary adenomas offer suitable models for studying some phases of exocytosis and membrane retrieval.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00691254
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  • 81
    Digitale Medien
    Digitale Medien
    The ultrastructure of primary cerebral rhabdomyosarcoma (1982)
    Springer
    Acta neuropathologica 56 (1982), S. 307-310 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Primary rhabdomyosarcoma ; Brain tumor ; Ultrastructure ; Basal ganglia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Primary intracranial rhabdomyosarcoma is extremely rare. A case of primary rhabdomyosarcoma in the left basal ganglia is described in a 2-year-old boy. The investigations revealed no primary lesion elsewhere except in the brain. At the electron-microscopic level, the majority of the cells contained specific microfilamentous bundles, which were either distributed at random or organized in myofibrils identified by their cross striations with primitive Z band formation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00691264
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  • 82
    Digitale Medien
    Digitale Medien
    The brain in extreme respiratory acidosis (1982)
    Springer
    Acta neuropathologica 58 (1982), S. 87-94 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Hypercapnia ; Rat brain ; Ultrastructure ; Cerebral edema
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary It is presently debated how much cellular acidosis contributes to brain cell damage during ischemia and hypoxia. To study the influence of acidosis occurring in the absence of energy failure, extreme hypercapnia was produced in anesthetized, artificially ventilated, and well oxygenated rats by increasing the inspired CO2 concentration until arterialPCO2 reached 150 or 300 mm Hg. At these CO2 tensions intracellular pH falls from a control value of about 7.05 to about 6.85 and 6.65, respectively. After 45 min the brains were fixed in perfusion and processed for light and electron microscopy. AtPaCO2 150 mm Hg no clear neuronal abnormality was detected, but atPaCO2 300 mm Hg some neuronal changes were observed. Notably, the nuclei showed slightly coarser chromatin than normally. In a few nerve cells mild swelling of mitochondria and dispersion of polysomes as well as detachment of ribosomes from the endoplasmic reticulum appeared. In both groups, slight to moderate astrocytic edema developed. Thus, even extreme hypercapnia, with its acompanying marked tissue acidosis, alters ultrastructure in the brain only to such a moderate extent that irreversible cell damage is unlikely. We conclude, therefore, that acidosis occurring during ischemia or hypoxia is detrimental only if pH is further lowered and/or if it occurs in conjunction with cerebral energy failure.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00691646
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  • 83
    Digitale Medien
    Digitale Medien
    The effects of chlorpromazine and phenobarbital on vasculogenesis in the cerebellar cortex (1982)
    Springer
    Acta neuropathologica 57 (1982), S. 306-308 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Blood vessel ; Brain ; Development ; Neuro-active ; Drugs ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The morphological effects of two chemically different neuroactive drugs (chlorpromazine and phenobarbital) on vasculogenesis in rat cerebellum were examined to determine the presence of vascular alterations. Therapeutic dosages of both drugs were chronically administered to separate groups of maternal rats beginning on days 10, 13, 15, 18, and 21. In chlorpromazine-treated animals the specific length of blood vessels was most severely reduced in the Purkinje cell layer. Animals treated with phenobarbital demonstrated an initial reduction in specific length in the Purkinje cell layer but returned to control values by day 21 postnatal (p.n.). Blood vessels in the molecular and granular layers showed little change. The observed changes have been discussed in relation to possible mechanisms and and their relationship to neurogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00692188
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  • 84
    Digitale Medien
    Digitale Medien
    Cellular and nuclear volumetric alterations during differentiation of normal hamster cheek pouch epithelium (1982)
    Springer
    Archives of dermatological research 273 (1982), S. 307-318 
    Details
    ISSN: 1432-069X
    Schlagwort(e): Morphometry ; Oral mucosa ; Keratinocytes ; Cell and nuclear volume ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The aim of this investigation was to determine whether volumetric changes occurred in differentiating layers of stratified squamous epithelium. Samples of cheek pouch mucosa from 5 hamsters were obtained, prepared for electron microscopy using carefully controlled methods, and electron micrographs obtained from defined basal, spinous and granular layers of the epithelium. Stereological point counting procedures were used to determine the ratio of nucleus to cytoplasm for each of the defined cell layers. From direct measurement of nuclear profiles, major and minor axes were transformed to diameters of circles of equivalent area and it was thus possible to obtain an estimate of nuclear volume. Using the previously determined nuclear-cytoplasmic ratios the volume of cytoplasm and hence cell volume, could be estimated for the cell layers. Between basal and granular layers, nuclear-cytoplasmic ratios decreased from 0.42 to 0.08, whereas cytoplasmic and cellular volumes increased progressively from 248 to 1052 μm3 and from 352 to 1144 μm3, respectively. Nuclear axial ratios were highest in the granular layers. These methods can be used in a variety of comparative ultrastructural studies of epithelia, and will also prove valuable in generating additional biological information from more conventionally presented stereological data.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00409260
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  • 85
    Digitale Medien
    Digitale Medien
    Correlation of45Ca incorporation with maturation ameloblast morphology in the rat incisor (1982)
    Springer
    Calcified tissue international 34 (1982), S. 211-213 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Rat ; incisor ; ameloblasts ; enamel ; 45Ca autoradiography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Rats were injected with45Ca and horseradish peroxidase to determine the patterns of45Ca incorporation into incisor enamel and the morphological types of the overlying maturation ameloblasts.45Ca autoradiography showed no differences in the patterns of incorporation into enamel between routinely embedded and freeze-dried specimens. Enamel overlaid by ruffle-ended ameloblasts was much more heavily labeled while that overlaid by smooth-ended ameloblasts showed only moderate labeling. The observations lend further support to the hypothesis that the ruffle-ended cells are very active in mineralizing enamel and that the smooth-ended cells are in a passive, restorative phase.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02411236
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  • 86
    Digitale Medien
    Digitale Medien
    Ultrastructural localization and gradient of activity of alkaline phosphatase activity during rodent odontogenesis (1982)
    Springer
    Calcified tissue international 34 (1982), S. 273-279 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Odontogenesis ; Ultrastructure ; Alkaline phosphatase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The ultrastructural localization and gradient of activity of alkaline phosphatase were studied with respect to cell differentiation, matrix synthesis, and matrix mineralization in the incisor and molar teeth of 4-day-old Sprague-Dawley rats. The animals were perfused intracardially at room temperature with 2.5% glutaraldehyde in 0.1M sodium cacodylate (pH 7.4) with 3–4% sucrose. The jaws were dissected, immersion-fixed for 24 h, and the incisor and molar tooth germs removed. These were demineralized in 10% EDTA in NaOH (pH 7.4) with 7% sucrose. After reactivation of the enzyme with 0.1M MgCl in Tris-maleate buffer (pH 7.4) at 4°C, the teeth were incubated for alkaline phosphatase in a medium consisting of 6 ml 3% sodiumβ-glycerophosphate, 4 ml 0.2M Tris-HCl buffer (pH 9.2), 3 ml 1.6% MgSO4, 12 ml 0.5% lead citrate (pH⋍12), and 2.1 g sucrose. The pH was adjusted to 9.2 with 0.2M HCl, the volume made up to 30 ml, and the solution centrifuged for 10 min at 5000 rpm. Control teeth were incubated in medium minus the substrate. Finally, the specimens were routinely post-fixed and embedded for sectioning and examination with a Philips 300 electron microscope. A gradient of alkaline phosphatase activity was mapped along the developing teeth in the cells of the stratum intermedium, the proximal borders of the ameloblasts, the early dentine matrix, the predentine-dentine border, matrix vesicles, and the plasma membranes of odontoblasts and subodontoblast cells. The gradient of alkaline phosphatase activity was evident in the forming tooth from the cervical loop to the crown apex and was related to the cellular events, matrix synthesis, and matrix mineralization occurring during odontogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02411250
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  • 87
    Digitale Medien
    Digitale Medien
    Electron microscopy of avian osteopetrosis induced by retrovirus MAV.2-O (1982)
    Springer
    Calcified tissue international 34 (1982), S. 382-390 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Avian osteopetrosis ; Avian oncornavirus ; Ultrastructure ; Calcification ; Bone cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Diaphyseal tibial bone of 12.5 – 13-day and 19-day-old embryos and 20-day-old hatched chicks infected with retrovirus MAV.2-O were examined by transmission electron microscopy. The viruses were associated with lining osteoblasts and osteocytes. Whereas the infection of the osteoblast layer seemed to be a transient stage, virus association with osteocytes was a constant and main ultrastructural feature. The viruses were found either in the osteoid or in the periosteocytic space of the bone lacunae. They arose from dense cytoplasmic areas located near the cell plasmalemma via a budding process. The newly budded virus particles often had a large tail or a fine stalk-like process lost in the extracellular space. The viruses underwent calcification by deposition of inorganic material and were incorporated in the bone trabeculae. No production of virus was observed in typical osteoclasts with well-differentiated ruffled borders. The viral-induced avian osteopetrosis seemed to result from increased bone deposition through stimulation of osteoblast and osteocyte activities, whereas osteoclastic bone resorption seemed to be undisturbed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02411272
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  • 88
    Digitale Medien
    Digitale Medien
    Occurrence of actin-like protein in extracellular matrix vesicles (1982)
    Springer
    Calcified tissue international 34 (1982), S. 376-381 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Matrix vesicles ; Bone ; Actin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Preliminary indications of the occurrence of actin and myosin in crude matrix vesicle preparations have been reported previously. In the present study extracellular matrix vesicles from rat alveolar bone were isolated. They were further purified by a sucrose density gradient. SDS-polyacrylamide gel electrophoresis of the purified vesicles revealed the presence of a polypeptide with a molecular weight of 43 K daltons and with electrophoretic mobility identical to that of blood platelet actin. The limited proteolysis of both 43 K dalton vesicular polypeptide and actin byStaphylococcus aureus-V8-protease revealed three fragments with identical electrophoretic mobility. In addition, the vesicular preparations inhibited the activity of DNase I, a property typical of actin monomers. Filamentous material extracted from matrix vesicles showed ultrastructural features of F-actin. Reaction of this material with heavy meromyosin resulted in arrowhead formation, which is characteristic of acto-heavy meromyosin. The occurrence of actin in extracellular matrix vesicles may account for their budding from the osteoblastic plasma membrane, their possible motility in the matrix, and maintenance of the spherical shape.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02411271
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  • 89
    Digitale Medien
    Digitale Medien
    Changes in the total number of dentate granule cells in juvenile and adult rats: A correlated volumetric and 3H-thymidine autoradiographic study (1982)
    Springer
    Experimental brain research 46 (1982), S. 315-323 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Rat ; Dentate granule cells ; Volumetric analysis ; Adult ; Neurogenesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The total number of granule cells in the dentate gyrus was estimated in 17 male rats, four each aged 30, 120, and 200 days, and five aged 365 days. There is a substantial 35–43% linear increase between 1 month and 1 year. Two parameters of the granular layer are involved in the numerical change. First, total granular layer volume grows linearly with age. Second, average volume of a single granule cell nucleus in the ventral dentate gyrus decreases with age. Older rats tend to have a larger granular layer filled with more and smaller cells. In another group of 21 male rats, 3H-thymidine injections were given on four consecutive days during juvenile (30–33, n = 6) and adult life (60–63, n = 5; 120–123, n = 6; 180–183, n = 4). All animals survived to 200 days of age. The proportion of labeled mature granule cells and labeled presumptive granule cell precursors were determined in anatomically-matched slices. With older ages at injection, there is a decline in labeled mature granule cells and a concurrent increase in labeled precursors. These data are compatible with the constant level of granule cell increase determined volumetrically. Most of the late granule cells originate nearly simultaneously along the base of the main bulk of the granular layer; very few are found in the dorsal tip (septal extreme) and ventral tip (temporal extreme). This study is the first demonstration of a net numerical gain in a neuronal population during adulthood in the mammalian brain. Since the granule cells play a pivotal role in hippocampal function, these data suggest that their influence grows with age.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238626
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  • 90
    Digitale Medien
    Digitale Medien
    Radioautographic study of 3H-GABA uptake in the oculomotor nucleus of the cat (1982)
    Springer
    Experimental brain research 48 (1982), S. 137-143 
    Details
    ISSN: 1432-1106
    Schlagwort(e): GABA uptake ; Radioautography ; Ultrastructure ; Oculomotor nucleus ; Cat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The uptake of tritiated γ-aminobutyric acid (3H-GABA) in the oculomotor nucleus of the cat was studied, using light and electron microscopic examination of radioautograms after intracerebral in vivo administration of the amino-acid. A glial uptake by oligodendrocytes was seen together with a neuronal uptake of the tracer in a certain type of axon terminals found in synaptic contact with both dendrites and soma, some of them exhibiting all the ultrastructural features of motoneurons. Previous neurochemical, electrophysiological and immunocytochemical studies indicate that GABA might well be the inhibitory neurotransmitter in the vestibuloocular reflex arc. The present results show that a morphological substrate exists for the presumed postsynaptic GABAergic inhibition of ocular motoneurons, at least in the oculomotor nucleus of the cat.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00239581
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  • 91
    Digitale Medien
    Digitale Medien
    Amygdalar inputs to ADH-secreting supraoptic neurones in rats (1982)
    Springer
    Experimental brain research 48 (1982), S. 420-428 
    Details
    ISSN: 1432-1106
    Schlagwort(e): ADH-neurone ; Amygdala ; Rat ; Supraoptic nucleus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Effects of amygdala stimulation on the discharge activity of antidromically identified supraoptic neurosecretory neurones were studied in male rats anaesthetized with urethane. Stimulation of the medial and the basal amygdala produced excitation or inhibition of discharge activity both in phasically firing (“phasic”) and in continuously firing (”continuous”) neurones. More “phasic” neurones were excited than were inhibited after medial amygdala stimulation. On the other hand, fewer “continuous” neurones were excited by stimulation of the either amygdala area than were inhibited. This difference of responsiveness between “phasic” and “continuous” neurones is statistically significant. Synaptic inputs to supraoptic neurosecretory neurones after amygdala stimulation were also observed in rats with a lesion of the stria terminalis. Supraoptic nucleus stimulation activated antidromically 14 of the 336 amygdala neurones tested. Since “phasic” neurones have been identified as ADH-secreting neurones, it is concluded that ADH-secreting neurones in the rat supraoptic nucleus receive predominantly excitatory synaptic inputs from the medial amygdala and these amygdalar synaptic inputs are mediated by pathways which are at least in part monosynaptic and are not included in the stria terminalis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238618
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  • 92
    Digitale Medien
    Digitale Medien
    Multiple connections of medial hypothalamic neurons in the rat (1982)
    Springer
    Experimental brain research 46 (1982), S. 383-392 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Electrophysiology ; Hypothalamus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The responses of 700 single neurons in the hypothalamus to electrical stimulation of the preoptic area, limbic structures, and midbrain were studied to determine the location of neurons with multiple inputs and to identify by antidromic activation the projection areas of those neurons. Converging excitatory inputs, observed in 134 responsive hypothalamic neurons, were principally derived from the preoptic, limbic, and midbrain areas. Inputs from separate nuclei of the amygdala were noted in the response of individual hypothalamic neurons. Two classes of short latency transsynaptic responses to amygdala stimulation were defined, indicating either separate pathways from the amygdala to the medial hypothalamus or two types of fibers conducting at different velocities. Stimulation of single or multiple sites in the preoptic and limbic areas, as well as in the arcuate nucleus and medial forebrain bundle produced inhibition of hypothalamic neuronal activity. Most antidromically identified medial hypothalamic neurons projected to the preoptic area, median eminence (tuberoinfundibular neurons), or midbrain. Evidence is presented for collateral projections of tuberoinfundibular neurons to the preoptic area and reticular formation. Medial hypothalamic neurons received inputs from the preoptic area, lateral septal nucleus, amygdala, ventral hippocampus (subiculum), and fornix. These findings illustrate a pattern of reciprocal connections between the medial hypothalamus and limbic and midbrain structures. It was concluded that the hypothalamus contains a type of neuron that is equipped to perform complex integrations and to coordinate directly the behavior of neurons in a diversity of anatomical regions.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238633
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  • 93
    Digitale Medien
    Digitale Medien
    Transplantation of tectal tissue in rats (1982)
    Springer
    Experimental brain research 47 (1982), S. 437-445 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Rat ; Tectal transplants ; Host afferents ; Functional innervations
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Fetal tectal tissue was transplanted adjacent to the superior colliculus of neonatal rats. In mature recipient animals, ultrastructural studies provided evidence of host cortical synapses on cells within the transplants. To determine whether these synapses were functionally effective in driving transplant cells, tungsten in glass microelectrodes were used to record from single units in the transplants and the host cerebral cortex was electrically stimulated. Of the 214 tested units which were shown histologically to be within the transplants, 25 (11.7%) were orthodromically excited from host cortex at latencies of 15 ms or less (mean 7.3 ms). A further four transplant units were activated at relatively long latencies (40–300 ms). The presence of a functional host retinal input was also tested by electrically stimulating the host optic nerves. No transplant units were activated from these sites, apparently because very few electrode penetrations passed through the localized zones of optic axon distribution. The possible functional interrelationships between transplant and host are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00239361
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  • 94
    Digitale Medien
    Digitale Medien
    Identification of geniculo-tectal relay neurons in the rat's ventral lateral geniculate nucleus (1982)
    Springer
    Experimental brain research 45 (1982), S. 84-88 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Rat ; vLGN ; Geniculo-tectal relay cells ; HRP ; Golgi-method
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In the rat's ventral lateral geniculate nucleus (vLGN), geniculo-tectal relay neurons (GTR-neurons) could be identified by the retrograde transport of horseradish peroxidase (HRP) after injection in the superior colliculus (SC). GTR-neurons correspond to class III cells described by Brauer and Schober (1973) in Golgi preparations of the rat's vLGN. The distribution of GTR-neurons is restricted to the lateral subnucleus of vLGN. According to Swanson et al. (1974), the axons of these cells terminate in lower Stratum griseum superficiale and in Stratum opticum, Stratum griseum intermedium and Stratum album intermedium of SC. The GTR-neurons are characterized by very thick and long proximal dendritic segments which have a smooth surface. Dendrites branch preponderantly in their distal regions and only in this part form many multiform protrusions. There is some evidence that retinal axons terminate on these dendritic surface structures. The supposed differences in the afferent patterns between GTR-neurons in the vLGN and geniculo-cortical relay neurons in the dorsal lateral geniculate nucleus are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00235765
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  • 95
    Digitale Medien
    Digitale Medien
    The response of primary horizontal semicircular canal neurons in the rat and guinea pig to angular acceleration (1982)
    Springer
    Experimental brain research 47 (1982), S. 286-294 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Semicircular canal ; Vestibular ; Primary afferent neuron ; Rat ; Guinea pig
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In rats and guinea pigs, primary afferent neurons from the horizontal semicircular canal were divided into two categories, regular and irregular, on the basis of the regularity of their resting activity. Regular neurons tend to have higher average resting rates than irregular neurons and in response to a constant angular acceleration stimulus of 16.7 deg/s2 regular neurons tended to have lower sensitivity and longer time constants than irregular cells. Some irregular neurons are more sensitive to incremental accelerations than to decremental accelerations of the same magnitude, whereas regular neurons tend to show symmetrical sensitivity. In response to sinusoidal angular acceleration stimuli (fixed frequencies) in the range 0.01–1.5 Hz, cells which fired regularly at rest tended to have smaller gain and longer phase lag re acceleration at most frequencies than irregular cells. Transfer functions were obtained for averaged data for regular and irregular neurons separately in both species. In both species there is evidence of systematic variation between neurons within each category, and this systematic variation is obscured by averaging across neurons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00239388
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  • 96
    Digitale Medien
    Digitale Medien
    Postnatal developmental changes in the response of rat primary horizontal semicircular canal neurons to sinusoidal angular accelerations (1982)
    Springer
    Experimental brain research 47 (1982), S. 295-300 
    Details
    ISSN: 1432-1106
    Schlagwort(e): Semicircular canal ; Vestibular ; Primary afferent neuron ; Development ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary At birth primary horizontal semicircular canal afferent neurons in the albino Wistar rat have slow, irregular spontaneous activity and insensitive, sluggish, variable responses to sinusoidal angular acceleration stimuli. There are rapid changes in the gross morphology of the rat semicircular canal in the first 4–5 days after birth, and during this time there is a rapid increase in neural gain re acceleration. Irregular neurons in rats about 6 days old have gains in the same range as irregular neurons in adult rats. However, after the gross morphological growth is complete, there continues to be a decrease in phase lag re acceleration. The causes of this developmental change in phase are unknown. It could be produced by changes in the receptor-afferent-efferent complex or by changes in the cupula or cupula-hair-cell attachment. These results with sinusoidal accelerations confirm the developmental increase in sensitivity and decrease in time constant found with constant angular accelerations (Curthoys 1979b).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00239389
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  • 97
    Digitale Medien
    Digitale Medien
    α-Monofluoromethyldopa (MFMD) in combination withl-DOPA (1982)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 321 (1982), S. 28-31 
    Details
    ISSN: 1432-1912
    Schlagwort(e): α-Monofluoromethyldopa ; l-Aromaticaminoacid decarboxylase ; l-DOPA ; Blood pressure ; Catecholamines ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary We have investigated the interaction of α-monofluoromethyldopa (MFMD) with the effects of i.p. injectedl-DOPA (200 mg·kg−1) on blood pressure and tissue catecholamines in normal and spontaneously hypertensive rats (SHR). MFMD 10 mg·kg−1 (i.p.) effectively antagonizes thel-DOPA induced increase in heart dopamine (DA). This action is also seen after 15 or 50 mg·kg−1. The accumulation of DA in the brain is very much reduced by MFMD 50 mg ·kg−1 while after 15 or, especially, 10 mg·kg−1 more DA is formed in the rrain than afterl-DOPA alone, probably due to the peripheral decarboxylase inhibition which presents morel-DOPA to the brain. We conclude that MFMD 10 mg ·kg−1 gives a relatively selective peripheral inhibition of the decarboxylation ofl-DOPA and this dose combination was accordingly found to result in a reduction of blood pressure in conscious animals. This hypotensive response tol-DOPA was attenuated after MFMD 15 mg·kg−1 and was absent after MFMD 50 mg·kg−1. Interestingly, the hypotensive effect ofl-DOPA after MFMD 10 or 15 mg·kg−1 was more pronounced in SHR.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00586344
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  • 98
    Digitale Medien
    Digitale Medien
    Dose-response relationships in the thermoregulatory effects of capsaicin (1982)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 320 (1982), S. 97-100 
    Details
    ISSN: 1432-1912
    Schlagwort(e): Capsaicin ; Thermoregulation ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The hypothermic effect of capsaicin, the reduced responsiveness towards the hypothermic effect of the drug as well as the impairment of thermoregulation in a warm environment subsequent to the administration of different doses of capsaicin have been studied in rats. The mortality after capsaicin treatment has also been established. 1. Capsaicin given subcutaneously in doses of 1–10 mg/kg induced a dose-dependent fall in body temperature lasting for 2–5 h. A single dose of 10 mg/kg caused the most pronounced hypothermic effect reaching its maximum (3,4°C) after 107 min. After higher doses (20–50 mg/kg) the fall in body temperature was less, being similar to that observed after the administration of 1–2 mg/kg. 2. A decreased sensitivity towards the hypothermic effect of a test dose of 2 mg/kg capsaicin, as well as an impaired tolerance to high ambient temperature have been found in rats 2 weeks after the pretreatment either with a single dose of 20–50 mg/kg or fractionated administration of 50 mg/kg capsaicin. The fractionated administration of a dose of 50 mg/kg capsaicin proved to be beneficial in decreasing mortality without affecting the desensitizing effect of capsaicin pretreatment. 3. After single doses of capsaicin the hypothermic period was followed by a dose-dependent hyperthermia which lasted for at least 2 days. A close correlation between the prolonged hyperthermic action and the desensitizing effect of capsaicin administration has also been established. The possible relationship between the desensitizing and hyperthermia inducing effect of capsaicin is briefly discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00506307
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  • 99
    Digitale Medien
    Digitale Medien
    Guanfacine and clonidine: antihypertensive and withdrawal characteristics after continuous infusion and its interruption in the spontaneously hypertensive and normotensive rat (1982)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 319 (1982), S. 82-86 
    Details
    ISSN: 1432-1912
    Schlagwort(e): Guanfacine ; Clonidine ; Continuous infusion ; Withdrawal ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In conscious unrestrained spontaneously hypertensive and normotensive rats, prepared with permanently indwelling abdominal aortic catheters, the effects on blood pressure and heart rate of a 12-day continuous subcutaneous infusion of guanfacine (10 mg/kg/day) and clonidine (500 μg/kg/day) and sudden interruption of these treatments were studied. Both drugs significantly and consistently reduced the mean arterial pressure and heart rate throughout the infusion period in the SH rats, but not in the normotensive animals. The magnitude of the effects of both drugs in the SH rat were similar. Following withdrawal of treatment with guanfacine, a discontinuation syndrome was evoked, much less severe than that observed after suspension of the infusion with clonidine. The withdrawal syndromes were characterized by an overshoot of heart rate and a period of blood pressure lability. In spite of the ineffectiveness of guanfacine and clonidine to reduce blood pressure and heart rate consistently in the normotensive rat, similar withdrawal patterns as those found in the SH rat were observed. These findings are in general agreement with the results previously found in clinical studies in hypertensive patients. The spontaneously hypertensive rat may prove a suitable animal model for pre-clinical studies of discontinuation symptoms after cessation of treatment with antihypertensive drugs.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00491483
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  • 100
    Digitale Medien
    Digitale Medien
    Effect of halothane anesthesia on end-tidal $$P_{CO_2 } $$ and pattern of respiration in the rat (1982)
    Springer
    Pflügers Archiv 392 (1982), S. 244-250 
    Details
    ISSN: 1432-2013
    Schlagwort(e): Rat ; End-tidal $$P_{CO_2 } $$ ; Halothane anesthesia ; Respiratory pattern
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract End-tidal $$P_{CO_2 } $$ $$\left( {P_{ET_{CO_2 } } } \right)$$ and ventilation of the rat anesthetized with halothane were measured. The $$P_{ET_{CO_2 } } $$ measured by an infrared analyzer agreed well with the simultaneously measured $$Pa_{CO_2 } $$ in the range from 20–60 mm Hg (2.7–8.0 kPa). When the level of anesthesia was deepened by increasing the halothane concentration from 0.9–3.0%, minute ventilation was decreased progressively accompanied by a rise in $$P_{ET_{CO_2 } } $$ and the CO2 output was reduced. Halothane induced a progressive decrease in frequency of respiration (f) with almost constant or even slight increase in tidal volume (V T). Decrease inf was caused largely by the prolongation of expiratory duration (T E). Changes in inspiratory duration (T I) were small and the meanV T/T I ratio remained unaltered at different levels of anesthesia. These changes in respiratory pattern induced by halothane anesthesia contrasted with the simultaneous decrease inV T,f andV T/T I ratio and apparent changes of bothT I andT E reported in other species. Species differences in effects of anesthesia on ventilation were discussed. Restraining the rat on a stereotaxic apparatus with head holders, especially with ear bars, elicited an initial transient stimulation of ventilation which was followed by a strong depression.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00584304
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