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  • 2015-2019
  • 1985-1989
  • 1970-1974  (23)
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  • 1
    Electronic Resource
    Electronic Resource
    Untersuchungen über die lokale Gefäßwirkung mechanischer Vibrationen an der Katzenhinterextremität (1972)
    Springer
    Research in experimental medicine 157 (1972), S. 37-46 
    Details
    ISSN: 1433-8580
    Keywords: Mechanical vibration ; Limb blood flow ; Cat ; Myogenic vasoconstriction ; Denervation ; Mechanische Vibration ; Extremitätendurchblutung ; Katze ; Myogene Vasoconstriction ; Denervierung
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Um die zugrundeliegenden Mechanismen der Einwirkung mechanischer Vibration (M. V.) mit höherer Frequenz zu klären, wurden 25 auto-perfundierte Katzenhinterextremitäten mechanischen Sinusschwingungen (100 Hz; 0,4 mm Amplitude; Wirkzeit 60 min) ausgesetzt und die resultierenden Veränderungen des lokalen Strömungswiderstandes ermittelt. Untersucht wurden die Auswirkungen von M. V. unter normalen Perfusionsbedingungen, nach pharmakologischer Ganglienblockade (10–15 mg/kg Pendiomid) sowie während i.v. Dauerinfusion von 4 µg/min L-Noradrenalin. Außerdem wurde regelmäßig die Reaktivität des Gefäßbettes auf vorübergehende Perfusionsdruckerhöhung um 50–60 mm Hg getestet. — Unter M. V.-Einwirkung trat stets innerhalb 50 min erhebliche Widerstandszunahme im untersuchten Gefäßbett ein, bei unverändertem Perfusions- und Systemarteriendruck. Dasselbe Reaktionsmuster war nach Pendiomidgabe und Denervierung zu beobachten, während bei erhöhtem Ausgangstonus (Noradrenalininfusion) der lokale Strömungswiderstand unverändert blieb. Die Reaktivität der Widerstandsgefäße auf Innendruckerhöhung wies ebenfalls Abweichungen gegenüber dem Verhalten des unbeeinflußten Gefäßbettes auf. — Insgesamt sind die Versuchsergebnisse mit der Annahme erklärbar, daß längerdauernde Einwirkung mechanischer Vibrationen zu einer lokalisierten Erhöhung des Basaltonus der Widerstandsgefäße führt.
    Notes: Summary In 25 experiments the effects of high frequency vibrational stress (M. V.) on total vascular resistance in the autoperfused cat hind limb was studied by local application of mechanical sine wave oscillations (100 Hz; 0.4 mm amplitude) for 60 min duration. The experiments were performed by recording of limb blood flow and arterial perfusion pressure during control perfusion, after ganglion blockade (10–15 mg/kg b. w. Pendiomid), after complete limb denervation and during i.v. infusion of L-noradrenaline (4 µg/min). In addition the induced changes of limb vascular resistance by a short time elevation of perfusion pressure (50–60 mm Hg) were tested before and during the M. V. period. — By M. V. a definite increase of local vascular resistance regularly could be produced in the vibrated limb within about 50 min, perfusion pressure as well systemic arterial pressure generally being constant. An almost identical response pattern was observed in the denervated limb as well as after pendiomid. By a transitory elevation of perfusion pressure the M. V. constriction could be reversibly eliminated. If applied during a sustained increase of vascular resistance (noradrenaline infusion), M. V. was without effect. — The experimental results are consistent with the assumption, that prolonged M. V. stress is followed by a localized diminution of limb blood flow, which is probably due to a substantial elevation of myogenic basal tone of the resistance vessels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01851396
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  • 2
    Electronic Resource
    Electronic Resource
    Vertical bundles of dendrites in the neocortex (1972)
    Springer
    Anatomy and embryology 136 (1972), S. 213-223 
    Details
    ISSN: 1432-0568
    Keywords: Neocortex ; Dendrites ; Columns ; Rabbit ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In frontal and tangential paraffin sections through the sensory-motor cortex of the rabbit, vertical bundles of dendrites have been found. Each bundle consists of several apical dendrites of layer V pyramids and extends through layer IV into layer III/II where the dendrites begin to ramify. Electron microscopy reveals that within the bundle some of the dendrites approach each other so closely as to be separated by the extracellular space only. A vertical bundling of dendrites has, also been found in various regions of the sensory-motor cortex of the cat. — The hypothesis is put forward that the vertical bundles of dendrites are the morphological substrate of the vertical functional units deduced from electrophysiological observations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00519179
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  • 3
    Electronic Resource
    Electronic Resource
    Über die postnatale Entwicklung des Ganglion stellatum der Katze (Felis domestica) (1972)
    Springer
    Anatomy and embryology 136 (1972), S. 59-72 
    Details
    ISSN: 1432-0568
    Keywords: Stellate Ganglion ; Postnatal Development ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die postnatale Entwicklung des Ganglion stellatum der Katze wurde an 19 Tieren im Alter von 1 Tag bis zu 6 Jahren untersucht. Die Ganglien wurden durch Perfusion fixiert. Folgende quantitative Befunde wurden erhoben: 1. Das schnelle Wachstum der Nervenzellen und der nicht-neuralen Elemente führt von der 2. Woche an zu einer Abnahme der Nervenzellen pro Volumeneinheit. Nach dem 3. Monat scheint die Zahl der Nervenzellen gleichzubleiben. 2. Die Anzahl der Gliazellen pro Volumeneinheit steigt während der beiden ersten Wochen auf etwa das Doppelte des bei der Geburt vorhandenen Wertes. Nach Erreichen eines Maximums nimmt die Zelldichte bis zum Alter von 1 Jahr wieder ab. Die Entwicklung des Ganglion stellatum zeigt folgende histologische Veränderungen: 1. Das Wachstum der Nervenzellen ist mit strukturellen Veränderungen an Kern und Perikaryon verbunden. Nach Vollendung des 1. Lebensjahres treten im Cytoplasma der Nervenzellen autofluorescierende Granula auf. 2. Während der Phase der Gliazellzunahme sieht man zahlreiche Mitosen. Die ersten Markscheiden treten am 8. Tag auf. 3. Das interstitielle Bindegewebe ist in den ersten Monaten außerordentlich zart und zellarm. 4. In allen Altersstadien findet man Mastzellen.
    Notes: Summary The postnatal development of the stellate ganglion was studied in cats aged from 1 day to 6 years and fixed by perfusion with Bouin's fluid from the aorta. The following quantitative findings were obtained: 1. The number of nerve cells per unit volume decreases from the 2nd week after birth. This decrease in number is attributed to the rapid growth of the neuronal elements and to an increase in the number of non-neuronal cells. From the 3rd month, the number of the nerve cells remains constant. 2. The number of glial cells per unit volume increases during the first two weeks after birth to roughly twice the number noted at birth. During this period numerous mitoses are found. After reaching a maximum at about 15 days, the cell-density decreases up to the age of 1 year. During postnatal development of the stellate ganglion the following histological changes were observed: 1. Growth of the nerve cells is accompanied by structural changes of the nucleus and perikaryon. In the cytoplasm of the nerve cells autofluorescent granules appear in cats aged about 1 year. 2. The first myelin sheaths appear on the 8th day. 3. During the first few months, the interstitial connective tissue is poorly developed. 4. Mast cells are found at every stage of the postnatal development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00521102
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  • 4
    Electronic Resource
    Electronic Resource
    Prenatal ontogenetic history of the principal neurons of the neocortex of the cat (Felis domestica) a golgi study (1972)
    Springer
    Anatomy and embryology 136 (1972), S. 125-142 
    Details
    ISSN: 1432-0568
    Keywords: Prenatal ontogenesis ; Neocortex ; Cat ; Golgy study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The individual prenatal ontogenetic history of the horizontal neurons (the Cajal-Retzius cells) of layer I, the Martinotti neurons of layer VI, the pyramid-like neurons (the polymorphous or spindle cells) of layer VI, and the pyramidal neurons of layer V of the cat neocortex have been investigated. These neurons undergo, in the course of prenatal ontogenesis, a series of significant changes in their dendritic and axonic arborizations resulting in their complete structural transformation. Some of these changes have led to the appearance of new types of neurons quite different from the original in their morphological features as wells as in the territory of distribution of their axons. The horizontal neurons of layer I (superficial plexiform layer) come to assume the morphological characteristics of Cajal-Retzius cells late in prenatal ontogenesis. Also, the pyramid-like neurons of layer VI (deep plexiform layer) acquire the features of polymorphous (spindle) neurons of layer VI late in prenatal neocortical ontogenesis. Certainly, the resulting functional transformations that these neuronal changes cause are important and of great significance in the understanding of the organization of the mammalian neocortex. In the course of prenatal ontogenesis the following occur: the horizontal neurons of layer I lose their axonic connections with layer VI and acquire an increasing relevance in the structural organization of layer I; the pyramid-like neurons of layer VI lose their axonic and dendritic connections with layer I and undergo pronounced regressive changes in their dendritic and axonic arborizations; and the Martinotti neurons lose their axonic connections with layer I and also undergo regressive changes in their dendritic arborizations. In addition, the structural-functional interrelationships among these three neurons, which are quite prominent during early neocortical ontogenesis, fade away in the course of late prenatal ontogenesis and possibly disappear altogether by the time of birth in the cat. These three neurons are the basic neuronal elements of the early, precallosal organization (the primordial neocortical organization) of the mammalian neocortex. Phylogenetically, these three types of neurons are very old ones and have been described in the cerebral cortices of amphibians and reptiles. Therefore, it is not surprising that the early, precallosal organization of the mammalian neocortex should resemble the structural organization of the reptilian (general cortex) neocortex. It is postulated in this communication that these neuronal transformations are the result of a restructuring in the organization of the mammalian neocortex which follows the arrival of the callosal fibers and of a new type of corticipetal fibers at the pyramidal plate. this restructuring represents a transformation of the fibrillary-neuronal structure of the mammalian neocortex from its early, precallosal (reptilian) organization into a more distinctly mammalian one. The mammalian neocortical organization is characterized by the sequential maturation of several strata of true pyramidal neuronal systems. In the course of prenatal ontogenesis the fibrillar and neuronal elements of the early, precallosal neocortical organization lose progressively their relevance in the structural organization of the mammalian neocortex while the new pyramidal neuronal systems acquire an increasing relevance in it.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00519174
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  • 5
    Electronic Resource
    Electronic Resource
    Regionale Unterschiede in der Cytoarchitektonik der Kleinhirnrinde bei Mensch, Rhesusaffe und Katze (1972)
    Springer
    Anatomy and embryology 138 (1972), S. 329-346 
    Details
    ISSN: 1432-0568
    Keywords: Cerebellum ; Cytoarchitecture ; Man ; Rhesus monkey ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung In der Kleinhirnrinde von Mensch, Rhesusaffe und Katze lassen sich Unterschiede in der Zellgröße und Zellzahl in verschiedenen Kleinhirnabschnitten nachweisen. Im ältesten Kleinhirnabschnitt, dem Lobus nodulofloccularis sind die Purkinjezellen und die Körnerzellen stets größer als in den Lappen des Corpus cerebelli. Außerdem besteht noch eine Größendifferenz zwischen Wurm und Hemisphären. In den vermalen Abschnitten aller Kleinhirnlappen sind die Purkinjezellen und die Körnerzellen größer als in den dazugehörigen Hemisphärenanteilen. Daneben bestehen Unterschiede in der Zellzahl. Im Lobus nodulofloccularis ist die Zellzahl signifikant geringer als in den übrigen Kleinhirnabschnitten. Ähnlich wie bei der Zellgröße bestehen aber auch bei der Zellzahl Unterschiede zwischen den Hemisphären- und Wurmanteilen eines Kleinhirnlappens. In den Wurmabschnitten ist die Zellzahl geringer als in den Hemisphären. Die regionalen Unterschiede in der Cytoarchitektonik und das zahlenmäßige Verhältnis der Purkinjezellen zu den Körnerzellen bei Mensch, Rhesusaffe und Katze werden im Hinblick auf den evolutiven Status der Gehirne diskutiert.
    Notes: Summary In different parts of the cerebellar cortex of man, rhesus monkey and cat there are variations in the size and number of cells. In the lobus nodulofloccularis, the Purkinje cells and the granule cells are larger in diameter than in the corpus cerebelli. Moreover, the Purkinje cells and the granule cells in the vermal parts of the nodulofloccular lobe, the posterior lobe and the anterior lobe are always larger in size than in the hemispheres of these lobes. In addition there are differences in the number of cells: In the nodulofloccular lobe the number of cells per unit volume is significantly lower than in the different parts of the corpus cerebelli; in the vermal parts the number of cells is smaller than in the respective parts of the hemispheres. Thus there are parallels between the differences in size and in number of Purkinje cells and granule cells in the phylogenetic older (vermis) and younger (hemispheres) parts of the cerebellum. The regional differences in cytoarchitectonics of the cerebellar cortex in man, rhesus monkey and cat are discussed with respect to evolution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00520712
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  • 6
    Electronic Resource
    Electronic Resource
    Latency differences between inhibitory and excitatory responses of cat optic tract units (1972)
    Springer
    Experimental brain research 16 (1972), S. 60-74 
    Details
    ISSN: 1432-1106
    Keywords: Optic tract ; Latencies ; Centre-excitation ; Centre-inhibition ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Excitatory and inhibitory responses of on- and off-centre neurones were elicited by stimuli restricted to the receptive field centres of optic tract units. The latencies of these responses were measured for various stimulus intensities and durations. Latencies depend upon: 1. the total effective luminance, including stimulus and background; 2. the luminance of the test spot relative to threshold luminance: latency changes for a particular light increment near threshold are larger than in the higher supra-threshold range; 3. the latencies of inhibitory responses are further influenced by the activity of the neurone before the onset of inhibition. A comparison of the latencies of excitatory and inhibitory responses showed that, following incremental light stimuli, the off-centre neurones became inhibited before the on-centre neurones were excited. The actual latency difference was a function of stimulus intensity and previous neuronal activity. Following light-off inhibitory responses were again faster, but the difference in time between the inhibition of on-centre neurones and the excitation of off-centre neurones was smaller than for the corresponding on-responses. It is suggested that the earlier onset of inhibitory responses is important for the release of reciprocal inhibition between on- and off-centre neurones in the lateral geniculate body.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233374
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  • 7
    Electronic Resource
    Electronic Resource
    The pattern in the projection of the intracerebellar nuclei onto the nucleus reticularis tegmenti pontis in the cat. An experimental anatomical study (1972)
    Springer
    Experimental brain research 16 (1972), S. 140-160 
    Details
    ISSN: 1432-1106
    Keywords: Nucleus reticularis tegmenti pontis ; Cerebellar nuclei ; Experimental anatomy ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intensity and distribution of degeneration in the nucleus reticularis tegmenti pontis (N.r.t.) were mapped in silver impregnated sections following stereotactic lesions of the intracerebellar nuclei. Confirming previous results (Brodal and Szikla, 1972) fibres from the interpositus-lateralis-complex, reaching the N.r.t. by way of the crossed descending limb of the brachium conjunctivum, supply the main central part of the N.r.t. from rostral to caudal. The interpositus posterior does not appear to take part in this projection, nor do the ventralmost parts of the lateral cerebellar nucleus (NL). The caudal part of the latter appears to give off more fibres than its rostral part. Rostral and caudal parts of the interpositus anterior (NIA) appear to contribute approximately equally. Fibres from both nuclei terminate in a largely overlapping fashion in the central main regions of the N.r.t. On the whole the NIA projection is situated a little more medially than the NL projection (Fig. 8). Within both projections caudal parts of the nuclei tend to project somewhat more medially than lateral parts, especially caudally. Certain findings suggest that there may be more detailed topical relations. The organization in the cerebellar-nuclear projection onto the N.r.t. corresponds in principle to the pattern found for its other afferent contingents (especially from the cerebral cortex, Brodal and Brodal, 1971). In spite of wide overlapping there is some degree of topical order.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233994
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  • 8
    Electronic Resource
    Electronic Resource
    Inhibitory interaction in the cat's lateral geniculate nucleus (1972)
    Springer
    Experimental brain research 14 (1972), S. 210-226 
    Details
    ISSN: 1432-1106
    Keywords: Cat ; Lateral geniculate body ; Postsynaptic inhibition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Spike activities of optic tract fibers and corresponding relay cells were recorded simultaneously in layers A and A1 of the dorsal lateral geniculate nucleus of the cat. Light stimuli of various diameters were shone into the receptive field center of these unit pairs and their input/output ratios were determined. An increase of the stimulus size leads to an impairment of the input/output ratio in on-center and off-center relay cells. This suppressive effect has approximately the same latency as the excitatory response. Intracellular recordings suggest that the inhibitory effect of the surround is due to a postsynaptic process. Inhibitory postsynaptic potentials occur during and — under certain stimulus conditions —before the excitatory response. The short latency of these IPSPs suggests that they result from the activity of adjacent units with the same RF characteristics as the recorded neuron. This inhibitory input is not restricted to the RF periphery but may also be activated by stimulation within the RF center. Most neurons are also inhibited by units with antagonistic center responses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234800
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  • 9
    Electronic Resource
    Electronic Resource
    Cutaneous mechanoreceptors influencing impulse discharges in cerebellar cortex. I. In mossy fibers (1972)
    Springer
    Experimental brain research 15 (1972), S. 245-260 
    Details
    ISSN: 1432-1106
    Keywords: Cerebellum ; Cutaneous mechanoreceptors ; Mossy fibers ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This paper gives an account of single mossy fiber responses when three types of mechanical stimulation are applied to the forefoot and hindfoot of the cat which is either decerebrate and unanesthetized or lightly anesthetized by pentothal or chloralose. The mechanical stimuli were applied either to footpads (brief pulses, taps, or longer square pulses or ramps) or to the hairy skin by air jets. Recording of single mossy fibers was extracellular by glass microelectrodes that were inserted into the granular layer of the cerebellar cortex or the subjacent white matter. As described in previous papers computer averaging techniques usually of 64 responses have been employed to enhance reliability. Taps evoked pure excitatory responses from many mossy fibers, which were usually brief high frequency bursts resembling those evoked by nerve volleys. Usually the threshold displacement was less than 0.2 mm and thresholds as low as 0.01 mm were observed. There were often considerable differences in the intensities of responses from different pads of the same foot. Successive pulses of mechanical stimulation evoked mossy fiber responses of diminished intensity. Longer mechanical stimuli with square or ramp onsets evoked various admixtures of phasic and tonic responses. Hair stimulation was often a very effective excitant, the receptive field for a single mossy fiber usually covering a considerable area of foot and leg. Taps and pressure to the pads were also effective in inhibiting the background discharge of some mossy fibers, and admixtures of excitatory and inhibitory actions were observed. The results are discussed in relationship to the discharges evoked in primary afferent fibers by cutaneous mechanoreceptor stimulation. They provide an intermediate stage of information between mechanoreceptor stimulation and the response of Purkyně cells as described in the next paper.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235910
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  • 10
    Electronic Resource
    Electronic Resource
    The facial nucleus of cat: Antidromic and synaptic activation and peripheral nerve representation (1972)
    Springer
    Experimental brain research 16 (1972), S. 161-183 
    Details
    ISSN: 1432-1106
    Keywords: Facial nucleus ; Topographical representation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The facial nucleus (FN) of the cat was studied by electrophysiological method for (1) general characteristics of the FN neurons during antidromic activation, (2) topographical representation of the peripheral branches of the facial nerve and (3) synaptic activities induced in the FN neurons following peripheral facial nerve stimulation. Stimulation of either peripheral branches or the genu of the facial nerve produced negative field potential of 2–3 mV in the FN. The field potential had a latency of less than 1 msec, refractory period of 2–3 msec and a relatively short duration. During double shock testing of the antidromic field potentials, the test potentials were suppressed (after initial recovery from the refractory period) for a duration of up to 80–100 msec. Intracellular analysis revealed that antidromic firing of the FN neuron is composed of M, IS, SD spikes. The rise time of spike potentials ranged from 0.23 msec to 0.53 msec and fall time 0.73 msec to 4.7 msec. The duration of the spike after-hyperpolarization varied from 6 msec to 60 msec with latencies to peak of 1.5 msec to 14 msec. Double shock testing showed that the summation effect of the afterhyperpolarization was greater at shorter time intervals. The latencies of the spike potentials varied from 0.46 msec to 1.1 msec for peripheral nerve stimulation and 0.18 msec to 1 msec for genu stimulation. The conduction velocity of the facial nerve ranged from 25 m/sec to 75 m/sec. These results were compared with the known characteristics of other cranial and spinal motoneurons. Topographical representation of the peripheral branches of the facial nerve was that the PA was represented solely in the medial aspect, TZ mainly in the dorsal aspect of the intermediate portion and BL in the ventral aspect of the intermediate and mainly in the lateral aspect of the nucleus. Stimulation of peripheral facial nerve produced negative field potentials in the FN or induced EPSPs in the FN neurons with latencies of 4–7 msec. The synaptic inputs were found mainly in the medial aspect of the FN by PA stimulation. These synaptic inputs were discussed as being relayed through the trigeminal nucleus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233995
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  • 11
    Electronic Resource
    Electronic Resource
    Visual perception in cats after environmental surgery (1972)
    Springer
    Experimental brain research 15 (1972), S. 405-423 
    Details
    ISSN: 1432-1106
    Keywords: Visual perception ; Visual cortex ; Visual deprivation ; Discrimination learning ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This report describes a series of experiments testing the behavioral significance of orientation sensitive cells in the cat's visual cortex. Cats used for this purpose were raised with one eye (VE) viewing a field of vertical lines and the other eye (HE) viewing a field of horizontal lines. This experience simplified their cortical physiology, and is thus called “environmental surgery”. Cells with elongated fields were found to be activated monocularly: those driven by the VE had vertically oriented receptive fields, while those activated by the HE had horizontally oriented fields. These animals were tested, using one eye at a time, on a series of visual discriminations: a) flux discrimination, b) tests for selective response to vertical and horizontal lines, c) discrimination between two lines differing only in orientation, d) discrimination between mirror image stimuli, and e) evaluation of inter-ocular transfer on these discriminations. The threshold tests for orientation discrimination gave the clearest results: there were small but consistent differences in performance between the VE and HE which depended on the orientation of the lines being discriminated. There was also evidence that the animals responded to different parts of a stimulus with the VE and HE. As a group, the experimental cats showed less interocular transfer of visual discriminations than the normal controls. However, surprisingly, there was also evidence for much functional equivalence between the two eyes. Possible explanations for this are considered and it is suggested that an animal's ability to make pattern discriminations is not rigidly determined by the shape and orientation of its receptive fields.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234126
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  • 12
    Electronic Resource
    Electronic Resource
    Analysis of the activity evoked in the cerebellar cortex by stimulation of the visual pathways (1972)
    Springer
    Experimental brain research 15 (1972), S. 278-288 
    Details
    ISSN: 1432-1106
    Keywords: Cerebellum ; Vision ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In cats without general anaesthesia electric stimulation of the optic chiasma evoked usually in the depth of the cerebellar cortex of lobuli VI and VII a sequence of waves at a latency of 7–10 msec which have been shown to be due to the mossy fibre input. A later wave at a latency of 18–20 msec was also sometimes found in isolation or in association with the early wave. This later field has been identified as due to the climbing fibre input. Unitary recordings have given support to this interpretation. Some correlation has been made with recordings obtained by electric stimulation of the superior colliculus and by flash stimulation of the retinae. It is concluded that the optic pathways project to the visual area of the cerebellar cortex through both mossy and climbing fibre inputs, although from this study based mainly on the laminar analysis of evoked fields, the former input seems to be more widespread and more consistently obtained than the latter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235912
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  • 13
    Electronic Resource
    Electronic Resource
    Visual experience as a determinant of the response characteristics of cortical receptive fields in cats (1972)
    Springer
    Experimental brain research 15 (1972), S. 289-304 
    Details
    ISSN: 1432-1106
    Keywords: Visual cortex ; Receptive fields ; Visual deprivation ; Neuronal plasticity ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cats reared with their visual world restricted to vertical lines for one eye and horizontal lines for the other had, in their visual cortices, units with elongated receptive fields that were either vertically or horizontally oriented. These receptive fields could be mapped only using that eye which had seen lines of the same orientation during development. Other units had diffuse, unresponsive receptive fields (Hirsch and Spinelli, 1970). Six cats, from the group above, were revived and allowed normal binocular viewing in an attempt to determine the possibility and extent of adding other types of receptive fields by giving other experiences to their visual systems. After exposure to a normal environment for up to 19 months it was found that indeed there had been a massive increase in the percentage of those classes of receptive fields that were either absent or weak at the end of the selective visual experience. Significantly, these receptive fields, acquired during binocular viewing, were very often binocular. The results, however, show that units whose response characteristics mimic the stimuli viewed during development were almost completely unaffected by normal binocular visual experience, i. e., they were monocularly activated and had the orientation appropriate for the stimuli viewed by the eye from which they could be mapped. Most impressive are a few units whose receptive field shape is almost a carbon copy of the pattern viewed during development. The data provide evidence that visual experience has a direct continuing and lasting effect on the functional connectivity of cells in the visual cortex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235913
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  • 14
    Electronic Resource
    Electronic Resource
    Cat optic tract and geniculate unit responses corresponding to human visual masking effects (1972)
    Springer
    Experimental brain research 15 (1972), S. 441-451 
    Details
    ISSN: 1432-1106
    Keywords: Optic tract ; Lateral geniculate nucleus ; Cat ; Backward masking ; Forward masking
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Stimuli leading to backward and forward visual masking in man were presented to the cat. Responses of single units in the optic tract and the lateral geniculate nucleus were measured. 2. The results of these measurements have been compared with human psychophysical data obtained under the same stimulus conditions. The possibility of comparison between the two kinds of data is discussed. 3. From this comparison it is concluded that the time course of both backward and forward masking is fully determined by mechanisms localized in the retina. The response duration and the antagonistic behaviour of ON- and OFF-center units are responsible for backward masking whereas the effects of the lateral inhibition may be responsible for forward masking. 4. Some suggestions are done in order to explain how the perception is mediated by the cooperation of the signals of ON- and OFF-neurons. Firstly, firing of the ON-units followed by firing of the OFF-units is the condition necessary for the perception of one brief flash. Secondly, two rapidly succeeding ON-excitations which are not separated by an OFF-excitation do not lead to the perception of separate flashes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236401
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  • 15
    Electronic Resource
    Electronic Resource
    A cerebellar projection onto the pontine nuclei an experimental anatomical study in the cat (1972)
    Springer
    Experimental brain research 16 (1972), S. 115-139 
    Details
    ISSN: 1432-1106
    Keywords: Pontine nuclei ; Cerebellar nuclei ; Experimental anatomy ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fibres passing from the intracerebellar nuclei to the pontine nuclei proper have been noted only by few students. In the present study this projection is analysed by mapping with the Nauta (1957) and Fink and Heimer (1967) methods the degeneration which occurs in the pontine nuclei following stereotactically placed electrolytic lesions in different parts of the intracerebellar nuclei in the cat. Cerebellopontine fibres come from the lateral cerebellar nucleus (NL) except its ventralmost part, and from the rostral but probably not from the caudal part of the interpositus anterior (NIA) and the interpositus posterior. The fibres end in three fairly well circumscribed regions of the pontine nuclei: a longitudinal column in the paramedian pontine nucleus, a column in the dorsolateral nucleus and one in the dorsal peduncular nucleus. Fibres from the NL as well as the NIA appear to end in all three regions, but the possibility of a more specific distribution cannot be excluded. Parts of the projection areas in the pons appear to be specific to cerebellar afferents, while other parts overlap with terminations of cerebropontine fibres, especially from SmI and SmII. The findings support the conclusions arrived at in recent studies of the cerebral corticopontine projections by P. Brodal (1968a, 1968b, 1971a, 1971 b) that the pontine nuclei are very precisely organized. The general principles in the organization of the corticopontine and cerebellopontine projections appear to be similar.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233993
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  • 16
    Electronic Resource
    Electronic Resource
    Schwellenerregung, zeitliche summation und impulsreaktionsfunktion in der retina der katze: Temporale rezeptive felder retinaler ganglienzellen (1972)
    Springer
    Experimental brain research 15 (1972), S. 212-224 
    Details
    ISSN: 1432-1106
    Keywords: Retina ; Receptive field ; Temporal summation ; Ganglion cell ; Time constant ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Mit Hilfe der Schewellensummation für Reize wachsender Dauer und mit zwei zeitlich getrennten Reizen wurde die Impulsreaktionsfunktion retinaler Ganglienzellen gemessen. Bei einer Reizgröße von 15′ Durchmesser und einer Hintergrundsbeleuchtung von 0.5 asb ergibt eine Exponentialfunktion eine gute Über-einstimmung mit den Meßwerten. Alle Neurone folgten dem Bloch-Gesetz (Is · T = const.) für kurze Reize mit einem kontinuierlichen ×bergang zu einer konstanten Schwelle. 2. Die einzelnen Zeitkonstanten wurden den jeweiligen Schwellensummations-kurven entnommen. Die mittlere Zeitkonstant beträgt 75 ms für On-Zentrum-Neurone und 126 ms für Off-Zentrum-Neurone. Das D-System der Off-Zentrum-Neurone ist gegenüber kurzen gegenüber langen Reizen unempfindlicher als das B-System der On-Zentrum-Neurone. 3. Kurze und lange Zeitkonstanten wurden sowohl in der zentralen als such in der peripheren Retina gedunden, kurze jedoch häufiger bei großer Exzentizität. 4. Die auf die Hintergrundsbeleuchtung begozene Zentrumsempfindlichkeit für kurze Reize ist vereinbar mit einer Schwellenerregung, die im Mittel für alle rezeptiven Felder als gleich groß angesehen werden kann. 5. Das der äumlichen Summation analoge Zeitsummationsverhalten führt zu dem Konzept eines zeitlichen rezeptiven Feldes.
    Notes: Summary 1. The impulse-response function of the retina was estimated at the ganglion cell level by comparing the temporal summation curve with the corresponding time integral. With a test spot of 15′ in diameter and at a background luminance of 0.5 asb, an exponential function with different time constants was found to be a good approximation. All neurons followed Bloch's law, Is · T = c, at short stimulus durations. With increasing stimulus durations, luminance threshold approached a constant. 2. The time constant for each receptive field was taken from the corresponding threshold summation curve. The mean value for on-center fields was 75 ms and for off-center fields 126 ms. The D-system was less sensitive than the B-system. 3. Short time constants were found primarily within a radius of 20° from the area centralis, whereas long time constants were obtained predominantly in the outer periphery. 4. The sensitivity of receptive field centers at short stimulus durations is consistent with an invariant threshold excitation, defined by the dimensionless value of the excitability integral. 5. Spatial and temporal summation are described by the concept of spatiotemporal receptive fields.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235583
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  • 17
    Electronic Resource
    Electronic Resource
    Cutaneous mechanoreceptors influencing impulse discharges in cerebellar cortex. II. In Purkyně cells by mossy fiber input (1972)
    Springer
    Experimental brain research 15 (1972), S. 261-277 
    Details
    ISSN: 1432-1106
    Keywords: Cerebellum ; Cutaneous mechanoreceptors ; Mossy fibers ; Purkyně cells ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This paper gives an account of single Purkyně cell responses when three types of mechanical stimulation, as in the previous paper, are applied to the forefoot and hindfoot of the decerebrate unanesthetized cat. Attention was concentrated on the effects of brief mechanical pulses to the footpad. Recording was extracellular by glass microelectrodes and special precautions were taken in identifying the spike responses as being due to a single Purkyně cell and in securing its effective isolation for our computer averaging techniques, as described in the previous papers. All Purkyně cells were in the ipsilateral anterior lobe in the lateral vermis or pars intermedia of lobules III, IV, V, except for a few recordings in the extreme rostral zone of lobule VI. Mechanical pulses or taps evoked responses from many Purkyně cells which were pure excitatory, pure inhibitory or admixtures thereof. The latencies of onset were usually in the range of 12–20 msec from the onset of the tap, which tends to be a little longer than the observed latencies for mossy fiber responses described in the preceding paper. There was often a considerable difference in the sizes of the responses evoked from different pads of the same foot, and the usual threshold for response was below 0.2 mm amplitude. Durations of responses were usually 10–20 msec for excitation and 50–100 msec for inhibition. Pressure pulses to the central foot pads of 2 sec duration evoked a wide variety of responses: brief phasic at “on” and “off” that could be admixtures of excitation and inhibition; almost pure tonic excitations or inhibitions that were well maintained during the 2 sec; phasic-tonic responses in various relative degrees. Usually 500 g was maximally effective and the threshold was below 100 g. Hair receptors were stimulated preferentially by brief air jets, there being brief excitatory or inhibitory responses much as with taps, but with rather longer latency. The effective area was usually fairly extensive over the hairy skin of the foot. In general the effects on Purkyně cells by cutaneous mechanoreceptors acting via mossy fibers were in accord with the mossy fiber responses reported in the preceding paper and with the well-known excitatory and inhibitory effects that are exerted by mossy fiber inputs on Purkyně cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235911
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  • 18
    Electronic Resource
    Electronic Resource
    Orientation specificity of visual cortical neurons after head tilt (1972)
    Springer
    Experimental brain research 14 (1972), S. 312-317 
    Details
    ISSN: 1432-1106
    Keywords: Orientation specificity ; Visual neurons ; Head tilt ; Orientatiton ; Variations ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The orientation specificity of the receptive fields of single neurons in primary visual cortex of the cat varied as a function of sustained head tilt in a sample of 33 cells. The types of variation suggested analogies to certain psychophysical phenomena. Orientation specificity of visual cortical cells may in part be determined by information from non-visual afferent systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00816165
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  • 19
    Electronic Resource
    Electronic Resource
    A quantitative analysis of the motoneuronal depression produced by increasing the stimulus parameters of afferent tetanization (1972)
    Springer
    Pflügers Archiv 333 (1972), S. 240-257 
    Details
    ISSN: 1432-2013
    Keywords: Motoneuron ; Excitation ; Inhibition ; Spinal Cord ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. In extensor alpha motoneurones, the effects of increasing the number of afferent fibres stimulated electrically, and the doubling of the threshold stimulus frequency for optimal repetitive firing was analysed quantitatively. 2. Three types of motoneurones could be distinguished according to their relative sizes, and to their discharge patterns during orthodromic stimulation of various strength and frequency: small (tonic), medium size (tonic) and large (phasic) motoneurones. 3. The excitability of the motoneurones was inversely related to their cell sizes. The order of inhibitibility depended on the experimental conditions. When the number of afferent fibres was increased by increasing the threshold stimulus strength by 2–4 X, at constant stimulus frequency, the mean firing rates of the small motoneurones were decreased very markedly. This procedure had practically no effect on the repetitive activity of the medium size motoneurones, whereas the large motoneurones could be driven better. 4. When the stimulus frequency was increased at constant stimulus strength, the large motoneurones were inhibited markedly, the medium size motoneurones less and the small motoneurones least,i. e., the inhibitibility of motoneurones was directly related to their cell sizes. 5. It was concluded that the high input resistance values in connection with postsynaptic inhibitory mechanisms could be responsible for more susceptibility of small motoneurones to inhibition, caused by electrically increasing the number of afferent fibres tetanized at constant stimulus frequency. To explain the greater susceptibility of large motoneurones to inhibition, caused by increasing the stimulus frequency from 100–200 Hz, a presynaptic mechanism was suggested. 6. The results were discussed according to several aspects of the size principle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00592686
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  • 20
    Electronic Resource
    Electronic Resource
    Electrical stimulation of vestibular nuclei: Effects on light-evoked activity of lateral geniculate nucleus neurones (1972)
    Springer
    Pflügers Archiv 334 (1972), S. 129-140 
    Details
    ISSN: 1432-2013
    Keywords: Vestibular Influence ; LGN ; Light Evoked Activity ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The light-evoked activity of single LGN neurones was recorded from light-adapted, anaesthetized cats. The neuronal responses to discrete illumination of the receptive field centre or periphery were compared to those obtained when the same photic stimulus was slightly preceded by electrical stimulation of the vestibular nuclei. It was found that the light-evoked responses of 82% of the LGN neurones studied were significantly affected by the vestibular stimulus. Both facilitatory and inhibitory effects were observed. There were no laterality effects. Similar modulation of LGN light-evoked activity was observed following stimulation of the mesencephalic reticular formation. Steps taken to eliminate various sources of experimental error are described. The above evidence suggests that the LGN is not a mere relay station but rather a structure where sensory interaction occurs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00586786
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  • 21
    Electronic Resource
    Electronic Resource
    Spermatogenesis in animals as revealed by electron microscopy (1972)
    Springer
    Cell & tissue research 125 (1972), S. 497-505 
    Details
    ISSN: 1432-0878
    Keywords: Chromatoid bodies ; Spermatozoa ; Cat ; Jensen's ring ; Centriole ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The first indication of differentiation of the Jensen's ring has been detected in an early stage of spermiogenesis of Felis catus Linné when the pair of centrioles takes up a position immediately beneath the plasma membrane. The chromatoid bodies appear in the early spermatid cytoplasm through the nuclear pore complex. In a more advanced stage, such bodies have been found in association with the striated columns, the distal centriole or the proximal part of flagellum and the Jensen's ring. As the spermiogenesis proceeds, the bodies have decreased their size and density, and finally disappear in mature spermatozoa. The chromatoid bodies seem, therefore, to share with the centriole the capacity to form the connecting piece. As a consequence of disorganization of triplet microtubules of the centriole, a noticeable material appears in the center of lumen of the centriole to be identifiable as a distinct precursor of the central pair of axonemal complex. Microtubules are first developed as the sheath of principal piece of the sperm flagellum, originating from the plasma membrane surrounding the axonemal complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306656
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  • 22
    Electronic Resource
    Electronic Resource
    Die Ultrastruktur der Kapillaren der Kleinhirnrinde und das perikapilläre Gewebe (1972)
    Springer
    Cell & tissue research 128 (1972), S. 83-99 
    Details
    ISSN: 1432-0878
    Keywords: Capillaries ; Cerebellar cortex ; Cat ; Blood-brain-barrier ; Electronmicroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Die Kapillaren im Kleinhirn der Katze haben einen Durchmesser von 3,5–12 μ. Im Stratum granulosum finden sich vorwiegend engere, im Stratum moleculare und in der Purkinjezellschicht meist weitere Kapillaren. Die Endothelzellen bilden schmale Lamellen, die sich teilweise überlappen und durch „tight junctions“ miteinander verbunden sind. Vom umgebenden Kleinhirngewebe sind sie durch eine Basalmembran abgegrenzt, die sich häufig in zwei Schichten spaltet, zwischen denen Perizyten mit ihren Fortsätzen liegen. Diese sind vornehmlich im Stratum granulosum am Aufbau der Kapillarwand beteiligt. Um die Kapillaren bilden Astrozyten mit ihren Fortsätzen, zum großen Teil aber auch mit ihren Perikaryen, einen unvollständigen Mantel. An den von Astrozyten freien Anteilen der Kapillaroberfläche grenzen Oligodendrozyten, Körnerzellen und Golgizellen mit ihren Perikaryen direkt an die Basalmembran der Kapillaren. Purkinjezellen liegen dagegen nicht unmittelbar der Kapillare an, sondern sind immer durch eine Schicht von Korbzellaxonen und Gliafortsätzen von der Basalmembran getrennt. Kapillaren mit einem Durchmesser von mehr als 10 μ besitzen einen perikapillären Raum. Dieser ist sowohl gegen die Glia als auch gegen das Endothel der Kapillare durch eine Basalmembran abgegrenzt. Im perivaskulären Raum findet man Perizyten, Fibroblasten und zirkulär verlaufende kollagene Fasern.
    Notes: Summary The capillaries in the cerebellar cortex of the cat have a diameter varying from 3.5 to 12 μ. In the granular layer the capillaries have a smaller diameter than those in the molecular and the Purkinje-cell layer. The endothelium forms slender lamellae which partially overlap. These lamellae are connected with each other by tight junctions. The capillaries are separated from the pericapillary compartment by a basement membrane which often splits into two layers; in between these layers processes of pericytes are located. The pericytes make up a part of the capillary wall mainly in the granular layer. Around the capillaries the astrocytes form an incomplete glial sheath with their processes and also with their pericaryon. Those parts of the capillary basement membrane which are not covered by astrocytes or their processes, are in contact with oligodendrocytes, granule cells or Golgi cells. The Purkinje cells have no intimate contact to the capillary, they are always separated from the basement membrane by a thin layer of basket cell axons and processes of astrocytes. The capillaries with a diameter greater than 10 μ often have a perivascular space. This space is separated from the endothelium as well as from the nervous tissue by a basement membrane. In the pericapillary space pericytes, fibroblasts and circularly arranged collagenous fibers are located.
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    URL: http://dx.doi.org/10.1007/BF00306890
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  • 23
    Electronic Resource
    Electronic Resource
    Adenosine triphosphatase activity in the carotid body of the cat (1972)
    Springer
    Cell & tissue research 130 (1972), S. 455-462 
    Details
    ISSN: 1432-0878
    Keywords: Carotid body ; Cat ; ATPase ; Histochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Three kinds of nucleoside phosphatases were demonstrated histochemically in the cat carotid body with nucleoside triphosphate, nucleoside disphosphate and nucleoside monophosphate as substrates. Each of these enzyme activities exhibited the substrate specificity respectively. The nucleoside triphosphatase activity showed specific localization in association with the parenchymal cells of the carotid body. The electronmicroscopy revealed that the reaction product was located on and between the two apposing plasma membranes of type I and type II cells, of a type II cell and its wrapping axons and of the intricate basal infolding of a type II cell itself. Some possible functions of the adenosine triphosphatase in the carotid body are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306999
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  • 24
    Electronic Resource
    Electronic Resource
    Die Bestimmung der intestinalen Resorption von Herzglykosiden durch Messung der3H-markierten Glykoside im Portalvenenblut und in der Darmlymphe bei Katzen (1969)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 264 (1969), S. 406-419 
    Details
    ISSN: 1432-1912
    Keywords: Intestinal Absorption ; Cardiac Glycosides ; Blood of Portal Vein ; Intestinal Lymph ; Cat ; Intestinale Resorption ; Herzglykoside ; Portalvenenblut ; Darmlymphe ; Katze
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The cardiac glyoosides digitoxin, ouabain, digoxin and peruvosid labelled with3H were injected into tied intestinal loops of anaesthetized cats in situ. The absorbed glycosides were measured in the blood of the portal vein and in the intestinal lymph. At the same time the3H-activity was measured in the blood of the peripheral circulation, in the bile and in the urine. 2. Calculation of the amount of glycosides totally absorbed from the3H-concentration in the blood of the portal vein and the circulation volume (bubble-flow-meter) gave the following absorption rates as a percentage of the administered dose per hour: digitoxin 56%, digoxin 42%, peruvosid 26% and ouabain 10%. 3. The amount of glycosides passing into the lymph during 1 hour was found to be only 0.006 to 0.02% of the amount offered. In lymph3H-activity cannot be measured earlier than 5 min after the administration of the labelled glycosides. The3H-concentration in the lymph did not equal that measured in the blood of the peripheral circulation until at least 1 hour after the administration and always remained below the3H-concentration of the blood in the portal vein. This proportion remained unchanged even if digitoxin was administered as an emulsion in oil instead of an aqueous solution. From the time course of3H-concentration it might be concluded that the glycosides do not pass directly to the lymph after absorption but indirectly by way of the blood. 4. The amount of glycoside excreted in the bile is for peruvosid 15,5% of the amount absorbed, for ouabain 1,9%, for digoxin 1,4% and for digitoxin 0,8%. The3H-activity excreted in urine is very small and can be disregarded. 5. Chromatographic analyses of the bile revealed, that in the case of digoxin, 4/5 of the amount excreted were unchanged, in the case of digitoxin and ouabain 2/3 and in the case of peruvosid only 1/4. In the lumen of the tied intestinal loops and in the tissue of the small intestine the glycosides were hardly metabolised.
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    URL: http://dx.doi.org/10.1007/BF01002379
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  • 25
    Electronic Resource
    Electronic Resource
    Über die Gefäßversorgung des Corpus callosum der Katze (1969)
    Springer
    Anatomy and embryology 128 (1969), S. 28-39 
    Details
    ISSN: 1432-0568
    Keywords: Arterial supply ; Corpus callosum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An 27 Katzen beiderlei Geschlechts wurde die Blutversorgung des Corpus callosum untersucht. Dabei wurden folgende Befunde erhoben: Der Balken der Katze wird im Bereich des Rostrum und Genu sowie im vorderen und mittleren Truncuabschnitt aus der Arteria cerebri anterior versorgt und zwar über Äste, die den Arteriae pericallosae und den Arteriae genu corporis callosi entstammen. Diese Äste wurden als Arteriae callosi superiores und inferiores bezeichnet. Lediglich im hinteren Truncusabschnitt und im Splenium erfolgt die Versorgung neben Ästen der A. pericall. auch über solche der Arteriae cerebri mediae und posteriores. Die Blutgefäße treten dolchartig in den Balken ein, teilen sich dann baumartig weiter auf und gehen in ein Capillarnetz über, das in Richtung des Nervenfaserverlaufes ausgezogen ist. Auf in der Literatur bereits bekannte, aber oft vernachlässigte Besonderheiten der Arteria carotis interna und des Circulus arteriosus wird hingewiesen.
    Notes: Summary In investigations on 27 cats of both sexes, the arterial supply of the corpus callosum was studied. The findings are as follows: In the region comprising rostrum and genu as well as in the fore and middle trunk sections, blood supplied by branches of the arteriae pericallosae and the arteriae genu corporis callosi which originate from the arteria cerebri anterior. These branches were designated arteriae callosi superiores and inferiores. However, in the posterior section of the trunk and in the splenium the blood is supplied by branches of the aa. pericall. and, in addition, by branches of the arteriae cerebri media and posteriores. The blood vessels penetrate the corpus callosum in bayonet fashion, then arborise and finally become a capillary network which is elongated in the direction of the course of the nerve fibres. Attention is drawn to peculiarities of the arteria carotis interna and the circle of Willis which, although known in the literature, are rarely referred to.
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    URL: http://dx.doi.org/10.1007/BF00522492
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  • 26
    Electronic Resource
    Electronic Resource
    Quantitative Untersuchungen an Gliazellen im Corpus callosum wachsender Katzen nach Perfusions- und Immersionsfixierung (1969)
    Springer
    Anatomy and embryology 128 (1969), S. 222-234 
    Details
    ISSN: 1432-0568
    Keywords: Postnatal development ; Fixation ; Neuroglia ; Corpus callosum ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Gehirne von Tieren aus 4 verschieden alten Würfen junger Katzen wurden teils lebensfrisch durch Perfusion, teils nach 24 Std durch Immersion fixiert und für Vergleichsuntersuchungen in Paraffin eingebettet. Bei Betrachtung der Gliazellen des Corpus callosum ergab sich: 1. Nach Perfusionsfixierung sind die Kerne der Gliazellen groß und elliptisch. Sie sind wasserklar und haben eine scharf gezeichnete Chromatinstruktur. Nach Immersionsfixierung 24 Std p.m. sind die Kerne dagegen klein und rund, homogen dunkel gefärbt und haben ein kaum zu erkennendes Chromatingerüst. 2. Nach Perfusionsfixierung sieht man im Balken der ganz jungen Tiere zahlreiche Mitosen. Sie fehlen bei den durch Immersion fixierten Geschwistertieren desselben Wurfes. 3. Die nach verschiedener Fixierung beobachteten Unterschiede in der Form der Gliazellkerne werden durch Messungen der Quer- und Längsachsen erfaßt.
    Notes: Summary In four litters of young cats, some of the brains were fixed by perfusion and the others by immersion. The material was embedded in paraffin and the neuroglia was investigated in sections through the corpus callosum. It was found that: 1. After fixation by perfusion the nuclei of the glia cells are large and elliptic. The caryoplasm is clear and there is a distinct structure of the chromatin. After fixation by immersion the nuclei of the same cells are small and round. The caryoplasm is dense and the structure of the chromatin is not clearly visible. 2. After fixation by perfusion mitotic figures are present. They are absent in the brains fixed by immersion. 3. Following different fixation, there are differences in the shape of the nuclei of the glial cells. These differences have been investigated in detail by measuring the diameters of the nuclei.
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    URL: http://dx.doi.org/10.1007/BF00521281
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  • 27
    Electronic Resource
    Electronic Resource
    The lateral cervical nucleus in the cat IV. A light and electron microscopical study after midbrain lesions with demonstration of indirect wallerian degeneration at the ultra-structural level (1969)
    Springer
    Experimental brain research 7 (1969), S. 51-67 
    Details
    ISSN: 1432-1106
    Keywords: Lateral cervical nucleus ; Midbrain lesions ; Nauta method ; Ultrastructural investigation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The lateral cervical nucleus (LCN) has been studied with the light and electron microscope after midbrain lesions in kittens of different ages, and in adult cats. It has been shown that nerve cells remain within the contralateral LCN after hemisection of the midbrain. performed on 1 day old kittens. The estimated number of these remaining cells was 3–19% in the different cases. No fibers descending to the LCN from levels rostral to the midbrain could be demonstrated in adult cats with the Nauta technique. A combined Nauta and electron microscopical investigation was performed on kittens operated on at different ages and allowed to survive varying times postoperatively. At the operations the LCN-axons were transected at midbrain level. The Nauta investigation demonstrated silver impregnation of degenerating LCN-neurons on the affected side of the same type as has been described recently in other neuronal systems following axonal transection. The ultrastructural study revealed electron dense degenerating dendrites and probably also nerve cells within the LCN. The dense degenerative changes were very similar to the dense degeneration in terminal boutons following transection of parent axons. The potential value of the findings for electron microscopical research in neuroanatomy is discussed. The results in terms of connections of the LCN are discussed in the light of known anatomical and physiological data of the LCN.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236107
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  • 28
    Electronic Resource
    Electronic Resource
    Integration konvergierender Afferenzen in der bulbären Formatio Reticularis der Katze (1969)
    Springer
    Experimental brain research 7 (1969), S. 143-157 
    Details
    ISSN: 1432-1106
    Keywords: Reticular formation ; Convergence ; Inhibition ; Cat ; Chloralose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Ein konditionierender corticaler Reiz inhibiert den somatischen Startlereflex bei Katzen unter Chloralosenarkose für eine Dauer von mehr als 200 ms. Die Interaktionen zwischen beiden Reizen laufen in der bulbären und pontinen Formatio reticularis ab. 2. Dem Startlereflex liegt eine polysynaptische Erregungsschleife zugrunde, die die bulbäre und pontine Formatio reticularis durchzieht. Die Resistenz der reticulären Neurone gegenüber repetitiver Stimulation wurde als Kriterium ihrer funktionellen Lokalisation auf dem polysynaptischen Reflexbogen gewertet. 3. Die corticale Inhibition wird im Verlaufe der polysynaptischen Erregungsschleife zunehmend stärker. Neurone, die von den Startlereflexafferenzen direkt erregt werden, werden durch den corticalen Reiz nicht inhibiert. Dies schliebt eine präsynaptische Inhibition der reticulopetalen Fasersysteme aus.
    Notes: Summary 1. The startle reflex evoked by cutaneous stimulation in cats under chloralose anesthesia is inhibited for more than 200 ms by a conditioning cortical volley. The interaction between the cutaneous and the cortical volley takes place in the bulbar and pontine reticular formation. 2. The startle reflex involves a series of reticular neurones. Resistance to repetitive stimulation has been determined to evaluate the functional localization of each neurone within this polysynaptic path. 3. Inhibition following the cortical volley becomes increasingly more effective along the course of the polysynaptic path and is completed within 5–6 ms. Reticular neurones excited directly by the spino-reticular afferents are not inhibited, thus excluding a presynaptic inhibition of the spinoreticular fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235440
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    Inhibitory and excitatory factors influencing the receptive fields of lamina 5 spinal cord cells (1969)
    Springer
    Experimental brain research 9 (1969), S. 284-306 
    Details
    ISSN: 1432-1106
    Keywords: Cutaneous receptive fields ; Spinal cord ; Cat ; Pain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Examination of cutaneous receptive fields (RFs) of lamina 5 cells in the lumbar spinal cord of decerebrate cats shows them to have three distinct zones with respect to mechanical and electrical stimulation. The mean response rate to both mechanical and electrical stimulation in zone 1 increases steadily up to the highest strengths used; in zone 2, surrounding zone 1 mainly proximally, mild stimuli reduce the mean rate, stronger stimuli increase it; in zone 3, mainly proximal to zone 2, all stimuli reduce the rate. Temporally, zone 1, electric shocks near threshold produce bursts of firing followed by inhibition. With increased stimulus strength, the bursts lengthen to a second or more. In zones 2 and 3, inhibition at all strengths is preceded at higher strengths by bursts of firing. Cold-blocking the spinal cord at lower thoracic levels reversibly increases the ongoing activity of these cells, increases the area of zones 1 and 2, and almost completely suppresses all inhibition. Stimulation of dorsal columns and threshold stimulation of distant dorsal roots inhibits ongoing and induced activity. Barbiturate decreases ongoing activity and the duration of firing produced by cutaneous electrical stimulation but does not decrease inhibition. These results are consistent with a model in which low-threshold fibres are excitatory only over a small central area of the RF of a lamina 5 cell (zone 1), high threshold fibres are excitatory over a larger area (zones 1 and 2), and low threshold fibres are inhibitory over the entire receptive field (zones 1, 2 and 3) with a slower time-course. This inhibition is tonically enhanced by descending influences in the decerebrate cat. It is suggested that the high and low threshold fibres correspond approximately to the small and large diametre fibres whose balance is the basis for the coding of pain in the theory of melzack and wall.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235240
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    Die Bedeutung der Vorderhirnkommissuren für die Koordination bilateraler EEG-Muster (1969)
    Springer
    Experimental brain research 7 (1969), S. 195-213 
    Details
    ISSN: 1432-1106
    Keywords: Corpus callosum ; EEG synchronization ; Homolateral sensory evoked potentials ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Spontaneous EEG-patterns and evoked potentials (EP's) of symmetrical cortical areas were recorded in chronic and acute cats before and after section of the corpus callosum, the commissura anterior and posterior and the massa intermedia. The spontaneous EEG was recorded without and with anesthesia, EP's after electrical stimulation of the fore-paws only during nembutal anesthesia. — No changes in the bilateral coordination of spontaneous and evoked EEG-patterns could be seen after commissurotomy (CT). The bilateral coherence of EEG-waves as revealed by cross-correlation is low already in the normal cats and does not change significantly after CT. The values of cross-correlation coefficients at T = ± 15 msec vary during one EEG-record between -0.25 and +0.25 in the somatosensory, suprasylvian and temporal areas (mean values slightly above 0). In the visual area occasionally positive values between 0.5 and 0.8 were seen, but also here a large variation was found in all animals and the mean values were below 0.1. No consistent phase shift between both sides was observed. EEG-patterns like spindles or arousal, still occurred together in both hemispheres after CT, the variability of their exact beginning or end was the same as in controls. Spontaneous spindles often lasted longer after section of the massa intermedia. Homolateral EP's in the somato-sensory area were still present after CT. Rhythmical afterdischarges could be restricted to the contralateral somato-sensory cortex even before CT.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239029
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    Functional organization of the vestibular afferents to the cerebellar cortex of frog and cat (1969)
    Springer
    Experimental brain research 9 (1969), S. 30-52 
    Details
    ISSN: 1432-1106
    Keywords: Climbing fibers ; Mossy fibers ; Vestibulo-cerebellar input ; Cat ; Frog ; Golgi cell inhibition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Field and unitary potentials evoked in the vestibulo-cerebellum of frog and cat following vestibular nerve stimulation were recorded with microelectrodes and correlated with their site of origin in the various layers of the cerebellar cortex. 2. In the frog, primary vestibular fibers project both as mossy and as climbing fibers onto the cerebellar auricular lobe. Secondary vestibulo-cerebellar fibers seem to end exclusively as mossy fibers in the auriculum. As a consequence of this dual projection, extra- and intracellular recordings from Purkinje cells in the auricular lobe show two kinds of responses to vestibular nerve stimulation: a) graded, repetitive firing mediated through mossy fiber-granule cell-parallel fiber pathways, and b) all-or-none burst responses caused by monosynaptic impingement of vestibular climbing fibers on Purkinje cells. 3. The field and unitary potentials evoked in the cat nodulus, flocculus and uvula following vestibular nerve stimulation are shown to be generated by mossy fibers exclusively. Considerable convergence of the two labyrinthine mossy fiber inputs to a given cerebellar area was found. 4. Interaction of contralateral and ipsilateral mossy fiber input at the level of the flocculus suggests that Golgi cell inhibition might operate not only as a simple inhibitory feedback loop, but also as a complex gating operator at the granule layer. 5. No short latency climbing fiber activation of Purkinje cells was observed following VIIIth nerve stimulation. Stimulation of the contralateral inferior olive evoked short latency climbing fiber EPSPs in Purkinje cells of the vestibulo-cerebellum. Suggestions are made as to the possible role of mossy and climbing fiber inputs to this area of the cerebellum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235450
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    Pyramidal control of fusimotor neurons supplying extensor muscles in the cat's forelimb (1969)
    Springer
    Experimental brain research 9 (1969), S. 96-115 
    Details
    ISSN: 1432-1106
    Keywords: Pyramidal tract ; Fusimotor Neurons ; Forelimb ; Extensor ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of cortical stimulation upon dynamic and static sensitivities of the sensory endings in muscle spindles have been analyzed. 63 single afferent fibers from the muscle spindles of the forelimb extensors: M. flexor carpi radialis, M. flexor digitorum communis and M. palmaris longus were isolated in dorsal root filaments in 20 adult cats under chloralose-urethane anesthesia. They were identified by their response to stimulation of the median nerve. 1. Surface anodal repetitive stimulation of the anterior sigmoid gyrus was found to produce an enhancement of static response of single Group II fibers. Effective area was localized in a restricted region which corresponded to the forelimb motor area. The effect was obtained without any concomitant muscle contraction. Similarly, the stimulation increased the resting discharges of the Group Ia fibers from the same muscles. 2. Stimulation of the same area in the cerebral cortex was also found to increase the dynamic sensitivities of primary sensory endings. The increase was revealed by an enhancement of initial burst discharge during relaxation period of a twitch contraction caused by median nerve stimulation. 3. These results indicate that stimulation of the forelimb motor area has a facilitatory effect on both the static and dynamic fusimotor neurons innervating the muscle spindles of the test muscles. 4. The effects were reproduced in pyramidal tract preparations in which the brainstem was cut either at the level of the midbrain except for the cerebral peduncle or at the level of caudal medulla oblongata sparing the pyramid. 5. The threshold for the fusimotor effects was less than 1.3–1.5 times threshold of the pyramidal tract discharge, when the best spot for eliciting the fusimotor response was chosen. These results indicate that the effects of cortical stimulation are mainly mediated by the fast conducting pyramidal tract fibers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00238324
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    Contrôle de l'activité des fibres fusimotrices dynamiques et statiques par la formation réticulée mésencéphalique chez le chat (1969)
    Springer
    Experimental brain research 9 (1969), S. 307-324 
    Details
    ISSN: 1432-1106
    Keywords: Muscle spindle ; Gamma motor control ; Mesencephalic reticular formation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Effects of repetitive stimulation of the mesencephalic reticular formation (MRF) on the static discharge and dynamic sensitivity of muscle spindle primary endings (soleus muscle) were studied in cats anaesthetized with Halothane (Fluothane). By progressive increasing the depth of anaesthesia three different fusimotor effects could be observed: 1. A static effect; the static discharge of the primary endings was strongly increased; the response to phasic stretch was decreased or remained unaltered. 2. A dynamic effect; the dynamic sensitivity of the primary endings was powerfully increased while the rate of discharge under static conditions was only slightly augmented. 3. A depressant effect; the static discharge and the dynamic sensitivity of primary endings were decreased. Repeated stimulation elicited successive static and dynamic effects. No specific regions within the MRF could be related to a particular effect.
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    URL: http://dx.doi.org/10.1007/BF00235241
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    Etude fonctionnelle du contrôle de l'activité des fibres fusimotrices dynamiques et statiques par les formations réticulées mésencéphalique, pontique et bulbaire chez le chat (1969)
    Springer
    Experimental brain research 9 (1969), S. 325-345 
    Details
    ISSN: 1432-1106
    Keywords: Muscle spindle ; Gamma motor control ; Reticular formations ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. During a progressive increase of Fluothane (Halothane) anaesthesia, repetitive stimulation of the mesencephalic retioular formation (MRF) produces several fusimotor effects — static, dynamic or depressant — on primary endings of soleus muscle spindles (Vedel et Mouillac-Baudevin 1969). 2. Transection of the brain immediately rostral to the site of stimulation may increase the dynamic effect but does not alter the static or the depressant effects. 3. A section of the rubrospinal tract does not modify the fusimotor effects elicited by stimulation of the MRF. 4. Transections of the spinal cord have shown that the pathways responsible for the transmission of these effects are mainly situated in the ipsilateral ventral and ventrolateral funiculi which contain the efferent fibers from the pontine reticular formation (PRF), from the bulbar reticular formation (BRF) and from the vestibular nucleus. 5. Contra and ipsilateral PRF stimulation produces the static fusimotor effect; contralateral stimulation from a small anterior region produces the dynamic effect. 6. Stimulation of the lateral part of the ipsilateral BRF elicits the dynamic effect while stimulation of the medial part elicits the static effect.
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    URL: http://dx.doi.org/10.1007/BF00235242
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    Die asynchrone und lokal umschriebene Reizwirkung von Mittelfrequenz-Dauerströmen im Hypothalamus der Katze (1969)
    Springer
    Experimental brain research 9 (1969), S. 164-182 
    Details
    ISSN: 1432-1106
    Keywords: Emotional behaviour ; Hypothalamus ; Electricalstimulation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. In order to compare the selective value of repetitive cathodal pulses of 8 c.p.s. and of continuous sine-wave alternating currents of 5000 c.p.s. (middle frequency current) when applied to brain tissue, explorations were made in the region of the hypothalamus that had yielded defence and/or flight reactions in earlier experiments. The region was explored by stimulating each point in turn with both current forms. At the same time measurement was made of the impedance of the brain tissue, and the effects produced by altering the time of rise of the middle frequency current on threshold of responses were also studied. The experiments were carried out on unanaesthetized, freely moving cats. 2. Both stimulation types produced affective (“emotional”) responses. The patterns elicited by low frequency cathodal pulse stimulation were often associated with stimulus-bound phasic muscle activity, i.e., flapping of ears, and twitching of whiskers, or, rotation of the head. Such extraneous motor effects were rarely obtained when continuous middle frequency currents were applied, and were tonic in character when present. 3. Mapping of reactive points revealed that the area producing defence or flight following middle frequency stimulation is smaller in size than the field delimited by means of repetitive cathodal pulse stimulation. These results strongly suggest that spread of current can be reduced by using middle frequency current stimulation. This apparently local (and hence highly selective) action is paralleled by a lower impedance of the brain tissue to the rapidly changing polarity of this current. 4. The hissing (and/or growling) associated with the defence pattern showed adaptation to suddenly rising middle frequency currents of 30 secs duration. An increase in threshold of hissing occurred when the time of rise of the current was prolonged. Flight, in contrast, was obtained at the same critical intensity regardless of the time of rise of current. 5. The nature of the stimulatory action of middle frequency current (examined in the peripheral nerve by Wyss) and the advantages presented by this new method of brain stimulation are briefly discussed.
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    URL: http://dx.doi.org/10.1007/BF00238329
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    The lateral cervical nucleus in the cat III. An electron microscopical study after transection of spinal afferents (1969)
    Springer
    Experimental brain research 7 (1969), S. 32-50 
    Details
    ISSN: 1432-1106
    Keywords: Lateral cervical nucleus ; Spinal lesions ; Ultrastructural investigation ; Degenerating boutons ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of terminal degeneration within the lateral cervical nucleus (LCN) after transection of its spinal afferent fibers 2 days–2 years earlier is described. The degeneration after 2 days was of both the neurofilamentous and dense type. The highest number of degenerating terminals, about 15%, was found after 4–5 days. Then most of the degenerating boutons were of the dense type. The degenerating terminals had synaptic contact with cell bodies and dendrites of LCN-neurons. Removal of the degenerating boutons seemed to be effected by a phagocytic cell present in increased number compared to the normal LCN. In cases with long survival times an increase in the number of astroglial filaments was observed. In an animal where the spinal afferents to the LCN had been cut 2 years earlier a decrease in medium size of the neurons was observed. The amount of dendritic spines was also considerably smaller than normally.
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    URL: http://dx.doi.org/10.1007/BF00236106
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    Inhibition in the medial geniculate body of the cat (1969)
    Springer
    Experimental brain research 7 (1969), S. 68-83 
    Details
    ISSN: 1432-1106
    Keywords: Medial geniculate body ; Inhibition ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Inhibitory activity in the cat medial geniculate body (MG) was examined by stimulating electrically and acoustically the input and output of the MG. 2. A longer and more profound depression of excitability occurs following a click-evoked potential in the MG than in the inferior colliculus (IC) in both anesthetized and unanesthetized states. Recovery is cyclic in the barbiturate MG preparation. 3. Electrical stimulation of the brachium of the inferior colliculus (BIG) evokes a field potential in the MG consisting of clearly distinguishable presynaptic and postsynaptic components. The presynaptic component recovers rapidly, while the postsynaptic component requires 100–200 msec for full recovery. This depression of excitability is localized within the MG since cortical ablation does not alter its occurrence. 4. Stimulation of the BIC mimics the effects of click stimulation on single units. Excitatory, inhibitory and reverberatory responses are evoked by the BIC shock. Suppression of single unit activity correlates with the depression of excitability following a BIC-evoked field response. 5. Cortical stimulation can evoke antidromic and trans-synaptic unit responses in the MG, as well as causing a variety of inhibitory effects and reverberation. In view of the fact that cortical ablation does not impair the recording of these responses to afferent stimuli, it is suggested that the cortical-evoked responses are at least partly mediated by antidromic conduction to MG. 6. Evidence is presented that inhibitory effects of both afferent and cortical stimulation are due to active inhibition of MG unit activity. Speculations are made as to the mechanisms producing inhibition and reverberation in the MG.
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    URL: http://dx.doi.org/10.1007/BF00236108
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    Electronmicroscopic observations on the structure of the pontine nuclei and the mode of termination of the corticopontine fibres an experimental study in the cat (1969)
    Springer
    Experimental brain research 7 (1969), S. 95-110 
    Details
    ISSN: 1432-1106
    Keywords: Electron microscopy ; Pontine nuclei ; Experimental neuroanatomy ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The electron microscopical changes occurring in the pontine nuclei following unilateral lesions of the primary sensorimotor cortex have been studied in 7 cats with a survival time from 2–23 days. A description is also given of the fine structure of the pontine regions in receipt of the fibres. These regions are shown in Fig. 1. The study shows that the boutons are practically only in synaptic contact with dendrites. The bouton density on these is only 16%. The boutons are of the en passage and terminal type, with the latter as the most common (Figs. 4a-e). The synaptic vesicles are rounded or elongated. The formaldehyde fixed material had 17.8% boutons with vesicles of the elongated type; the material fixed with a mixture of formaldehyde and glutaraldehyde had only 11.5% of such boutons. The degenerating boutons show the dark type of reaction and the majority of the corticopontine fibres are of the type shown in Figs. 4d and 4e. Astrocytes and microglial cells participate in the removal of degenerating boutons and terminal fibres. Degenerating boutons are present even at the 23 day stage and some have apparently only started to degenerate.
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    URL: http://dx.doi.org/10.1007/BF00235436
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    Electronic Resource
    Eine faktorenanalyse von schwellen subcorticaler reizantworten (1969)
    Springer
    Experimental brain research 8 (1969), S. 79-96 
    Details
    ISSN: 1432-1106
    Keywords: Evoked potential thresholds ; Factor analysis ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Zur Beschreibung von Korrelationen zwischen zahlreichen elektrophysiologischen Daten aus verschiedenen Hirngebieten wurde eine Faktorenanalyse nach der Hauptachsenmethode gerechnet. Ausgangsmaterial dieser Analyse waren Schwellen subcortical ausgelöster und abgeleiteter Antwortpotentiale auf Einzelreize. Das resultierende Faktorenmuster ermöglicht ein quantitatives Konzept der Schwellendetermination subcorticaler Reizantworten und zugleich ein Modell von Funktionsbeziehungen zwischen einigen Hirnstrukturen. Die Reizungen und Ableitungen erfolgten bei 35 encéphale isolé-Katzen mit Hilfe bipolarer Elektroden in folgenden Arealen: Amygdala, Hippocampus, Septum, N. dorsomedialis Thalami, Hypothalamus posterior und Formatio reticularis mesencephali. Es wurden 435 Korrelationskoeffizienten zwischen den Schwellen von 30 subcorticalen Verbindungen gebildet und zum Zwecke einer Datenreduktion durch eine Matrix von 5 Faktoren reproduziert. 1. Jeder Faktor repräsentierte hohe Schwellenkorrelationen zwischen den efferenten Projektionen jeweils eines Kerngebietes. Demnach nimmt im allgemeinen die Aktivität des Reizortes den größten Einfluß auf die Schwelle eines Antwortpotentials. Diese Hypothese ist durch pharmakologische Untersuchungen belegt worden [27] 2. Kovariationen von Reizantworten mit identischen Ableiteorten ergaben sich ausnahmslos, wenn die Latenzzeiten mehr als 11 msec betrugen. 3. Zusätzlich zeigte die Faktorenmatrix Schwellenkorrelationen zwischen: a) den hypothalamischen Efferenzen und mehreren hippokampalen Afferenzen langer Latenz (positive Korrelationen) b) retikulo-limbischen Verbindungen und „primären” Efferenzen von Amygdala und Hippocampus (positive Korrelationen) c) Antwortpotentialen, die durch Reizung der Formatio reticularis, und solchen, die durch Reizung des N. Amygdalae ausgelöst waren (negative Korrelationen) d) den Efferenzen des N. dorsomedialis Thalami und limbischen Projektionen langer Latenz zur mesencephalen Formatio reticularis (positive Korrelationen) Die Interpretation dieser Zusammenhänge bestätigt und erweitert einige bekannte Modelle von Beziehungen zwischen subcorticalen Kerngebieten. Abschließend wird mit Rücksicht auf die Linearität der mathematischen Methode die Anwendbarkeit der Faktorenanalyse auf Schwellen von Reizantworten diskutiert.
    Notes: Summary In 35 cats (encéphale isolé) evoked responses were elicited and recorded with bipolar electrodes from the amygdala, hippocampus, septum, dorsomedial thalamic nucleus, posterior hypothalamus, and mesencephalic reticular formation. Correlations between the thresholds of responses in different areas following stimulation of other areas were described by a factor analysis according to the principal axis method. 435 coefficients of correlation were calculated and reproduced by a matrix of 5 factors for the purpose of data reduction. Each factor represented high threshold correlations between the efferent projections of one region, which suggests that the activity of the stimulated site exerts a major influence on the evoked potential threshold. This is supported by pharmacological studies [27, 49]. Covariations of responses recorded in the same nucleus were always found, if the latencies exceeded 11 msec. The factor matrix indicated threshold correlations between: the efferent projections of the hypothalamus and several long latency afferent projections to the hippocampus (positive correlations); reticulo-limbic connections and “primary” efferent connections of the amygdala and hippocampus (positive correlations); evoked potentials following reticular and amygdaloid stimulation (negative correlations); the efferent projections of the dorsomedial thalamic nucleus and long latency limbic projections to the mesencephalic reticular formation (positive correlations). The interpretation of these relationships confirms and extends some well known models of relations between subcortical regions. The applicability of factor analysis to evoked potential thresholds is discussed with regard to the linearity of the mathematical method.
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    URL: http://dx.doi.org/10.1007/BF00234927
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    Interaction of defence and flight reactions produced by simultaneous stimulation at two points in the hypothalamus of the cat (1969)
    Springer
    Experimental brain research 8 (1969), S. 130-149 
    Details
    ISSN: 1432-1106
    Keywords: Emotional Behaviour ; Hypothalamus ; Electrical stimulation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The results presented in the present paper are an extension of preceding work devoted to exploration of the hypothalamic defence and flight fields using coaxial electrodes with small cathode. In 33 cats simultaneous stimulation was applied to two points which upon single stimulation had yielded defence, flight, or defence and flight respectively. Results were compared with those produced at either point alone. In 2 cats combined stimulation of a defence and a flight point was carried out with a stuffed cat present. 2. The latencies and rates of the vocal effects associated with defence (growling and hissing), and the latencies of flight (jump from the table) were measured. 3. Simultaneous stimulation of two points which had yielded defence, or of two points which had yielded flight resulted in facilitation (spatial summation) of the effects evoked: a more complete defence response associated with decrease of the latencies and increase in the rates of the vocal effects; decrease of flight latencies and increase of flight impetuosity. 4. Simultaneous stimulation of a defence point which had yielded growling at lower threshold than hissing, and of a point which had yielded flight resulted in facilitation of hissing. Growling and flight were often suppressed; when they occurred, latencies were lengthened and growling rates were increased somewhat. 5. Stimulation of a defence point with a dummy present produces striking (fending off). Simultaneous stimulation of a flight point resulted in facilitation of both hissing and striking. 6. It is concluded that the complex patterns obtained when defence is combined with flight are the result of facilitatory and inhibitory interaction between the elements of the individual patterns.
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    URL: http://dx.doi.org/10.1007/BF00234535
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    Räumliche summation und hemmungsvorgänge im receptiven feldzentrum von retina-neuronen der katze (1969)
    Springer
    Experimental brain research 8 (1969), S. 37-52 
    Details
    ISSN: 1432-1106
    Keywords: Retinal Ganglion Cells ; Spatial Summation ; Center Inhibition ; Dynamic Organisation of Receptive Fields ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. An retinalen Ganglienzellen der Katze wurde die räumliche Summation im receptiven Feldzentrum (KFZ) bei Dunkeladaptation und Helladaptation durch mittelpunktzentrierte Lichtreize verschiedener Flächengrößen untersucht. Als Kriterium dienten die Entladungsraten der ersten 200 und 500 msec nach Licht-an oder Licht-aus. Das Summationsverhalten wurde sowohl für Einzelneurone als auch gruppenstatistisch für die beiden Neuronen-Systeme B (on-Zentrum) und D (off-Zentrum) untersucht. 2. Die räumliche Summation ist auf den inneren Bereich des RFZ beschränkt: bei on-Zentrum-Neuronen steigt die Entladungsrate nur bis zu Reizflächen, die etwa 1/5 der Fläche des RFZ belichten, bei off-Zentrum-Neuronen bis zu Reizflachen von ca. 1/10 des RFZ. Bei Variation der Reizfläche zwischen 20 und 100% der Fläche des RFZ bleibt das Entladungsniveau konstant (asymptotischer Verlauf der Summationskurve). 3. Die Begrenzung der räumlichen Summation auf einen kleinen Bereich des RFZ beweist eine bereits im Feldzentrum wirksame Hemmung. Diese Zentrum-Inhibition begrenzt die Erregungssummation im RFZ bei zunehmender Flächengröße des Lichtreizes. 4. On- und off-Zentrum-Neurone unterscheiden sich in beiden Adaptationszuständen in der Höhe des Entladungsniveaus. Die Entladungsraten der on-Zentrum-Neurone nach Licht-an übertreffen um ein Mehrfaches die Entladungsraten der off-Zentrum-Neurone nach Licht-aus. Die Unterschiede sind gruppenstatistisch hoch signifikant. Die interneuronale Variabilität der Entladungsraten ist bei den onZentrum Neuronen erheblich geringer als bei den off-Zentrum-Neuronen. 5. Dunkel -und Helladaptation führt zu signifikantem Unterschied der Entladungsraten: bei Helladaptation liegt die Impulsrate beider Neuronentypen höher als bei Dunkeladaptation und der Summationsbereich ist um 5–10% größer. 6. Für die mathematische Beschreibung der Summationsverläufe ist die Hyperbel besser geeignet als die logarithmische und Potenzfunktion. Logarithmus- und Potenzfunktionen beschreiben den konstanten asymptotischen Teil der Summationskurven ungenügend und eigenen sich nur für den Kurventeil im innersten Summationsbereich. Die Bedeutung der Befunde für eine dynamische Interpretation der visuellen Feldorganisation und mögliche Beziehungen zur lateralen Umfeldhemmung werden diskutiert.
    Notes: Summary 1. Spatial summation of suprathreshold light stimuli within receptive field centers (RFZ) of retinal ganglion cells was investigated during dark and light adaptation in cats. The mean discharge rates for 200 and 500 msec following light on or off were the computed response criteria. The summation effects were analyzed for single neurones and statistically for grouped neuron populations of the two neuronal subsystems B (on-center-neurones) and D (off-center-neurones). 2. Spatial summation is restricted to a small part of the RFZ. On-centerneurones increase their on-discharge rates with increasing spot sizes, only if the stimulus illuminates less than 1/5 of the RFZ. The summating area of the off-centerneurones is smaller (about 1/10 of the RFZ). 3. The limitation of spatial summation to a small part of the RFZ indicates the existance of inhibition within the RFZ. This center-inhibition sets a constant limit for excitation summation in the RFZ. 4. The mean neuronal response rates for the 2 subsystems show significant differences: The on-discharges of the on-center-neurones exceed the off-discharges of the off-center-neurones by a factor of 3–5. These highly significant differences occur at both adaptation levels and are not due to different spontaneous activity. Interneuronal response variability of the off-center-neurones was twice as large as that of the on-center-neurones. 5. Change from dark to light adaptation had only a small but significant influence on summation properties. The poststimulus discharge rates were higher during light adaptation and the summating area was slightly larger (about 5–10%). 6. A comparative curve fitting procedure for three suitable mathematical functions revealed that the hyperbola describes the neuronal summation curves better than a logarithmic or power function. The latter do not fit the constant asymptotic part of the curve. The significance of the results for a dynamic interpretation of the organisation of visual receptive fields is discussed.
    Type of Medium: Electronic Resource
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    Electronic Resource
    Räumliche summation im receptiven feldzentrum von neuronen des geniculatum laterale der katze (1969)
    Springer
    Experimental brain research 8 (1969), S. 53-65 
    Details
    ISSN: 1432-1106
    Keywords: Lateral geniculate body ; Spatial summation ; Off-center-characteristics ; Geniculate transfer ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Die räumliche Summation im receptiven Feldzentrum von Neuronen des Corpus geniculatum laterale (CG-L) wird beschrieben und mit entsprechenden Untersuchungen an retinalen Ganglienzellen verglichen. Neben größerer interneuronaler Variabilität ergeben sich ausgeprägtere Unterschiede der Summationseigenschaften der on-und off-Zentrum-Neurone. Der effektive Summationsbereich von etwa 1/5 der Fläche des RFZ ist in Retina und CGL etwa gleich. 2. Die on-Zentrum-Neurone des CGL zeigen in beiden Adaptationszuständen einen ähnlichen Summationsverlauf wie in der Retina. Das Entladungsnieau ist im CGL jedoch erheblich geringer und nicht durch Unterschiede in der Spontanaktivität zu erklären. 3. Die Mehrzahl der off-Zentrum-Neurone des CGL zeigt bei DA inverse Summationsverläufe wie in der Retina: durchgehende Verminderung der Entladungsrate der off-Antworten bei Vergrößerung der Reizfläche im RFZ. Eine kleine Gruppe zeigt einen parabelförmigen Summationsverlauf mit Entladungszunahme bis zu Reizflächen von 10–30% der Fläche des RFZ und darauffolgender Entladungsminderung. Bei Helladaptation zeigen fast alle off-Zentrum-Neurone diesen Parabelverlauf. Das durchschnittliche Entladungsniveau ist von dem retinaler offZentrum-Neurone nicht signifikant verschieden. 4. Die interneuronale Variabilität der Summationsvorgänge im RFZ von CGLNeuronen ist gegenüber den retinalen Ganglienzellen deutlich größer. Dies gilt insbesondere für die off-Zentrum-Neurone. Das Summationsverhalten von CGLNeuronen läßt sich daher nicht wie in der Retina durch einen Funktionstyp beschreiben. 5. Die Befunde sprechen für eine Transformation des retinalen Eingangs der off-Zentrum-Neurone im CGL, während die on-Zentrum-Neurone außer der bekannten Frequenzuntersetzung keine wesentliche Umformung erkennen lassen.
    Notes: Summary 1. Spatial summation in the receptive field center of neurones of the lateral geniculate body (CGL) is limited by inhibition to a small part of field center. Variations of stimulus size are only effective if the stimulus is smaller than about 1/5 of the area of receptive field center. Thus, the active summating area of the field center in the CGL corresponds to that of the retina. Geniculate neurones, however, show less homogeneous responses and the summation properties of the two neuronal subsystems (on-center-and off-center-cells), show greater differences than in the retina. 2. The form of summation curves for the on-center-neurones of the CGL is similar to those of the retina at both adaptation levels. However, the average responses rates in the CGL are considerably lower. This is not due to differences of spontaneous activity. 3. The summation characteristics of off-responses of off-center-neurones of the CGL are quite different from those in the retina. In dark adaptation the majority of CGL neurones respond with decreasing discharge rates to increasing spot-sizes within the field center. A small number show an initial increase of discharge rates up to stimulus sizes of about 1/10 of the receptive field center before a decrease occurs. This parabolic summation type is typical for most off-center-neurones in light adaptation. The mean discharge levels are the same as those of the retinal offcenter-neurones. 4. The higher interneuronal variability of summation curves especially of the off-center-neurones of the CGL indicates a more complex determination of the discharge properties of CGL neurones. This functional differentiation of single neurones is congruent with the more complex structural and synaptic organisation in CGL. 5. With respect to spatial summation, the results indicate a transformation of the retinal input of the off-center-neurones at the geniculate level, whereas the oncenter-neurones are nearly unchanged.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234925
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    Electronic Resource
    Langfristige Verträglichkeitsprüfung mit Benperidol an der Katze (1969)
    Springer
    Psychopharmacology 14 (1969), S. 164-166 
    Details
    ISSN: 1432-2072
    Keywords: Benperidolum ; Cat ; Extrapyramidal Side Effect ; EEG ; Toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Daily doses of 1–10 mg Benperidol were given perorally to cats during 26 months. The general behaviour and the EEG were unchanged during the treatment, in particular no signs of dyskinesia were observed. After discontinuation of the administration, the behaviour and the EEG of the animals stayed normal. Thus no lasting and irreversible side effects could be observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00403690
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  • 44
    Electronic Resource
    Electronic Resource
    Effects of LSD on the spontaneous and evoked activity of retinal and geniculate ganglion cells (1969)
    Springer
    Psychopharmacology 15 (1969), S. 382-391 
    Details
    ISSN: 1432-2072
    Keywords: LSD ; Retina ; LGN ; Single Unit Activity ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of LSD 25 (i. v. injection) on the spontaneous and evoked activity of the visual system was investigated in cats. 50 γ/kg did not change significantly the ERG and the visual cortical evoked potential. The spontaneous discharge rate of 14 out of 21 retinal ganglion cells showed an increase which reached its maximum within 20–30 min and which could still be present 1 hour following the injection. One third of the retinal units showed a slight depression of their spontaneous dischaRge rate with about the same time course. Single units of the LGN showed about the same behaviour. The response to light stimulation was slightly increased in some units and light induced inhibition was slightly shortened. The possible mechanism of the LSD-effect on retinal ganglion cell activity is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00403713
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  • 45
    Electronic Resource
    Electronic Resource
    Responses of neurones in cat's abducens nuclei to horizontal angular acceleration (1969)
    Springer
    Pflügers Archiv 309 (1969), S. 285-309 
    Details
    ISSN: 1432-2013
    Keywords: Labyrinthine Stimulation ; Types of Abducens Neurones ; Frequency Analysis ; Cat ; Labyrinthreizung ; Abducensneurone ; Frequenzanalyse ; Katze
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Single cell activity was recorded extracellularly from neurones in cat's abducens nuclei in unanesthetized, decerebrate preparations. Two types of neurones were found. i) The motoneurones (type IIA) increased their firing linearly or exponentially to contralateral constant angular accelerations and decreased firing to ipsilateral rotation. The increased frequency was maintained at a constant level without any sign of adaptation. This constant level of maximum frequency was proportional to the logarithm of the acceleration applied. No significant differences of the frequency responses of tonic and silent motoneurones were found. The conduction velocities of the axons of spontaneously firing type IIA cells were slower than in silent neurones. Electrical stimulation of the contralateral VIIIth nerve led to activation of the type IIA cells; stimulation of the ipsilateral nerve resulted in inhibition of both spontaneous discharge and antidromic invasion of the motoneurones. ii) The type IA units increased their firing rate to ipsilateral rotation and ceased to discharge in response to contralateral rotation. They never were excited antidromically by stimulation of the VIth nerve. However, they were excited by stimulation of the ipsilateral VIIIth nerve. Their possible functional role in the vestibulo-ocular system was discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00587754
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  • 46
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    Electronic Resource
    Die Rolle „spezifischer” und unspezifischer Afferenzen für den Antrieb der Atmung, untersucht durch Reizung und Blockade von Afferenzen an der decerebrierten Katze (1969)
    Springer
    Pflügers Archiv 312 (1969), S. 189-205 
    Details
    ISSN: 1432-2013
    Keywords: Cat ; Decerebration ; Afferents to Respiratory Centers ; Medulla Oblongata ; Reticular Formation ; Katze ; Decerebrierung ; Afferenzen zu Atemzentren ; Medulla oblongata ; Formatio reticularis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung An 11 intercolliculär decerebrierten Katzen wurde geziegt, daß Kälteblockade eines eng umschriebenen Feldes auf der ventralen Oberfläche der Medulla oblongata, wie früher für anaesthesierte Tiere beschrieben, zu Atemstillstand führt, wenn die kontralaterale Stelle auf der Medulla oblongata, die Sinusnerven und die Vagi ausgeschaltet sind. Zu Atemstillstand kam es auch, wenn statt der Kälteblockade 2% Novocain durch lokale Superfusion bei gleichzeitiger Gegenspülung der Umgebung mit künstlichem Liquor angewandt wurde, oder wenn ein mit 1% Novocain getränkter Tupfer lokal aufgelegt wurde. Außerdem führte Kälteblockade zu Atemstillstand, wenn durch kontinuierliche auch während der Kälteblockade anhaltende elektrische Reizung eines N. femoralis oder hinterer Lumbalwurzeln an decerebrierten Katzen oder des Hypothalamus an einer anaesthesierten Katze Steigerungen der Ventilation ausgelöst worden waren. Elektrische Reizung eines Sinusnerven führte zu Atemsteigerungen. Bei Sinusnervenreizung während eines durch Kälteblockade ausgelösten Atemstillstands kam es zu rhythmischer Atmung. Aus diesen Untersuchungen wird geschlossen, daß mit der Ausschaltung der beschriebenen Felder auf der ventralen Oberfläche der Medulla oblongata am sonst desafferentierten Tier die Gesamtheit der für die zentrale CO2-Empfindlichkeit verantwortlichen Strukturen erfaßt ist, daß nach Ausschaltung der zentralen und der peripheren Chemosensibilität eine unspezifische Aktivierung der Atmungszentren unwirksam ist und daß die Atmungszentren zur Ausbildung einer rhythmischen Atmung von spezifischen Antrieben abhängig sind.
    Notes: Summary It was shown in 11 decerebrated cats, that cooling of a small and well defined area on the ventral surface of the medulla will cause respiratory arrest if the contralateral area of the medulla, the vagi and sinus nerves are eliminated. This confirms earlier observations obtained in anesthetized cats. Apnea was also produced by local superfusion of 2% procain with simultaneous flushing of the immediate surrounding area with mock spinal fluid. Local application of a small sponge soaked with 1% procain had the same effect. Electrical stimulation of femoral nerves or posterior roots which results in hyperventilation on the decerebrated cat failed to show any effect during periods of cold blockade. There was no respiratory response to direct stimulation of the hypothalamus in an anesthetized cat during cooling. Electrical stimulation of one sinus nerve caused an increase of ventilation. Sinus nerve stimulation during apnea induced by cold blockade resulted in rhythmical respiration. It is concluded from these experiments: Blocking of the area under discussion on the ventral surface of the medulla, inhibits all structures responsible for the central CO2-sensitivity in the deafferentiated animal. There was no response to non-specific stimuli of the respiratory center after elimination of central and peripheral chemosensitivity. The respiratory centers apparently depend on specific stimuli to support rhythmical respiration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00586928
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  • 47
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    Electronic Resource
    Defence, attack, and flight elicited by electrical stimulation of the hypothalamus of the cat (1969)
    Springer
    Experimental brain research 8 (1969), S. 113-129 
    Details
    ISSN: 1432-1106
    Keywords: Emotional behaviour ; Hypothalamus ; Electrical stimulation ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. Affective behaviour patterns produced by electrical stimulation of the hypothalamus were studied in unanaesthetized, freely-moving cats. Bipolar stimulation with coaxial electrodes and small cathode was used to elicit defence, attack or flight. The development of these responses was studied by varying stimulation strength. In some experiments a stuffed animal was introduced in order to study the reactions of the cat to changes in the environment during stimulation. 2. The following responses were evoked at threshold intensity: (i) growling reaction; (ii) hissing reaction; (iii) two types of flight — type a preceded by hastily looking to and fro as if in search of an exit, type b preceded by inspection of surroundings, in most cases associated with sniffing. 3. Increasing stimulation 1.5 times threshold often yielded combined patterns. At points yielding the growling reaction a defence response in which growls alternated with hisses was obtained. The points yielding flight type a sometimes yielded hissing followed by flight. Increasing stimulation at hissing points yielded either a defence reaction or the combined effect hissing-flight. 4. The growling reactions were obtained from the tuber region. The hissing responses were obtained from points above the tuber. The flight reactions, type a, were produced from the intermediate zone extending from the level of the preoptic area to the mamillary bodies and type b from the caudo-lateral hypothalamus. 5. The reactions of the cats to a dummy during stimulation varied depending on the type of response which had been evoked in the absence of the dummy. The defence reaction was converted into threatening and striking of the dummy, the combined effects into threatening, striking or biting, culminating in sudden flight. The dummy was ignored during stimulation of points yielding flight type a, but examined by sniffing during stimulation of points yielding flight type b.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234534
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    Electronic Resource
    Evidence for mediated transport of chloride in cat cerebral cortex in vitro (1969)
    Springer
    Experimental brain research 8 (1969), S. 219-231 
    Details
    ISSN: 1432-1106
    Keywords: Cerebral cortex in vitro ; Chloride transport ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The kinetics of the uptake of chloride by slices of cat cerebral cortex incubated in vitro have been studied for a wide range of concentrations of chloride and potassium in the incubation media. 1. In studies with 36Cl at a constant concentration of external K+, the rate of entry of chloride into slices of cat cerebral cortex (after equilibration with the fluid of the extracellular space) followed Michaelis-Menten kinetics with Vmax=7.7 μmoles/g/min and Km=245 mM. The kinetic data so described differ significantly from a curve describing simple diffusion (P 〈 0.02). 2. A clear dependence on concentration of K+ in the incubation medium was demonstrated. When external chloride was held constant at 6.8 mM and concentrations of potassium were varied over a range of 27–100 mM, the apparent rate of entry of chloride followed Michaelis-Menten kinetics with Vmax=0.191 μmoles/ g/min and Km=30.3 mM. 3. Under similar equilibrium conditions, the rate of influx of chloride was not statistically different from the rate of efflux, and the value for extracellular space (355 μl/g) derived by extrapolation from efflux data was of an identical order of magnitude to the value (352 μl/g) obtained from influx data. These values are essentially identical to those previously determined for chloride space of cat cerebral cortex in vivo (Bourke, Greenberg and Tower 1965). 4. The total, membrane-delimited content of chloride in cerebral cortex, as defined in these studies in vitro, was a function of the concentration of K+ in the incubation medium.
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    URL: http://dx.doi.org/10.1007/BF00234250
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  • 49
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    Electronic Resource
    Studies of the development and subsequent reduction of swelling of mammalian cerebral cortex under isosmotic conditions in vitro (1969)
    Springer
    Experimental brain research 8 (1969), S. 232-248 
    Details
    ISSN: 1432-1106
    Keywords: Cerebral cortex in vitro ; Edema ; Fluid compartmentation ; Chloride transport ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ionic parameters of incubation media which foster both the development and subsequent reduction of swelling of slices of cerebral cortex under isosmotic conditions of incubation in vitro are described. A linear relationship between increasing chloride concentrations in incubation media and progressive swelling of tissue slices (under conditions of constant temperature and K+ concentrations and isotonicity of incubation media) is demonstrated. Subsequent reduction of chloride concentration in incubation media together with reciprocal replacement by isethionate is associated with significant and characteristic reduction in the volume of tissue swelling when all other conditions of incubation, including isotonicity of the media, are kept constant. The ionic composition of the fluid of swelling under different conditions of incubation is derived together with the ionic composition and expected transmembrane potentials of the neuronal compartment of cerebral cortex in vitro. Mechanisms involved in the development and subsequent reduction of swelling of cerebral cortex in vitro are discussed, and proposals for possible clinical applications are suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00234251
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  • 50
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    Electronic Resource
    Verbesserung der Resorption von Helveticosid und Helveticosol durch Substitution der Hydroxylwasserstoffe an der Digitoxose (1969)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 262 (1969), S. 73-86 
    Details
    ISSN: 1432-1912
    Keywords: Strophanthidine Derivatives ; Toxicity ; Absorption ; Guinea-Pig ; Cat ; Strophanthidinderivate ; Toxicität ; Resorption ; Meerschweinchen ; Katze
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wurde die Wirksamkeit verschiedener Ester und Äther von Helveticosid und Helveticosol bei i.v. und intraduodenaler Zufuhr an Katzen und Meerschweinchen geprüft. 1. Bei i.v. Dauerinfusion waren Helveticosol und seine Derivate bei Meerschweinchen etwa doppelt so wirksam wie die analogen Helveticosidverbindungen. Bei der Katze bestand kein Unterschied. Die Monomethyläther Cymarin und Cymarol waren gleich oder sogar stärker wirksam, alle übrigen Derivate deutlich schwächer als die Ausgangssubstanzen. 2. Die tödlichen Dosen bei intraduodenaler Injektion lagen beim Meerschweinchen für einige Substanzen in gleicher Größenordnung oder niedriger als die Titer bei i.v. Infusion. Diese hohe enterale Wirksamkeit kann bei Helveticosid und seinen Derivaten durch eine Reduktion zu dem wirksameren Helveticosol, bei Estern außerdem durch eine Hydrolyse zu wirksameren Glykosiden vorgetäuscht werden. 3. Bei intraduodenaler Infusion an Katzen waren alle geprüften Ester und Äther wirksamer als Helveticosid und Helveticosol. Die aus dem Verhältnis der toxischen Dosen bei i.v. und intraduodenaler Infusion berechnete enterale Wirksamkeit lag zwischen 20 und 50%. 4. Unterschiede in der Dauer der intraduodenalen Infusion bei Katzen lassen sich berücksichtigen, wenn man von der theoretischen Annahme einer exponentiellen und vollständigen Resorption ausgeht und die Halbwertszeit für die Resorption berechnet. Die minimale Resorptionsgeschwindigkeit lag bei einigen Derivaten in gleicher Größenordnung wie bei Digoxin und Digitoxin. Es wird auf den Unterschied zwischen der auf Grund der pharmakologischen Wirkung bestimmten relativen enteralen Wirksamkeit und der Resorptionsquote hingewiesen. Letztere ist für die Verläßlichkeit der therapeutischen Wirkung eines Glykosids bei oraler Gabe maßgebend.
    Notes: Summary The efficacy of several esters and ethers of Helveticosid and Helveticosol was assayed by intravenous and intraduodenal administration to cats and guinea-pigs. 1. In guinea-pigs, Helveticosol and its derivatives were approximately twice as active on intravenous infusion as the analogous derivatives of Helveticosid; in cats there was no significant difference. The monomethylethers Cymarin and Cymarol were equally or slightly more potent, all other derivatives were weaker than the original compound. 2. In guinea-pigs the lethal doses of some compounds on intraduodenal injection were equal to or even lower than those on intravenous infusion. This may partly be accounted for by a reduction of Helveticosid and its derivatives to the more potent Helveticosol analogues, partly by a hydrolysis of the esters, yielding compounds of higher activity. 3. On intraduodenal infusion in cats, all the investigated esters and ethers were more active than Helveticosid and Helveticosol. The relative enteral activity calculated from the ratio of the toxic doses on intravenous and intraduodenal infusion varied between 20 and 50%. 4. Due to a delayed absorption from the gastrointestinal tract, the toxic dose falls with a reduced speed of intraduodenal infusion. Assuming an exponential and complete absorption, the half time of absorption was calculated. For some of the compounds investigated, the speed of absorption was comparable to that of Digoxin and Digitoxin. The difference between the relative enteral activities determined by comparing equiactive doses on enteral and parenteral administration and the percentages of the glycosides which are absorbed from the gastrointestinal tract is pointed out. The latter is of prime importance for obtaining reproducible effects after enteral administration.
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    URL: http://dx.doi.org/10.1007/BF00536819
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    Electronic Resource
    Morphologische Untersuchungen an der Glandula bulbourethralis der Katze (1969)
    Springer
    Cell & tissue research 101 (1969), S. 607-620 
    Details
    ISSN: 1432-0878
    Keywords: Glandula bulbourethralis ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Zusammenfassung Das Parenchym der Glandula bulbourethralis der Katze besteht aus weitlumigen, gebuchteten intraglandulären Gängen, in welche kurze, englumige, zumeist unverzweigte Tubuli einmünden. Der Drüse fehlt eine äußere Organkapsel, so daß ihre peripheren Tubuli stellenweise direkt zwischen den Fasern des quergestreiften M. bulboglandularis liegen. Die Drüsentubuli und die Buchten der intraglandulären Gänge sind mit einem einschichtigen Zylinderepithel ausgekleidet, auf den Gangfalten ist das Epithel abschnittsweise mehrreihig, Die sezernierende Epitheloberfläche ist durch die Ausbildung von interzellulären Sekretkapillaren vergrößert. Breite Zwischenzellspalten (Durchmesser etwa 1,5μ), in welche schlanke interdigitierende Cytoplasmafortsätze hineinragen, erstrecken sich von der Basalmembran bis kurz unter das Tubulusbzw. Ganglumen. Die lumenseitigen Zellgrenzen tragen einige stummelförmige Mikrovilli und besitzen zerklüftete Außenkonturen, die durch glykogenreiche Cytoplasmaprojektionen bedingt sind. Alle Epithelzellen sind reich an Mitochondrien. Die supranuklearen Abschnitte der meisten Gang- und Tubuluszellen enthalten Sekretgranula, welche im Elektronenmikroskop unterschiedliche optische Dichten aufweisen können. Die Granula enthalten ein PAS-positives, neuraminsäurehaltiges epitheliales Muzin, das in einzelnen Sekretkörnchen auch eine histochemische Reaktion auf Sulfatgruppen gibt. Alle Epithelzellen reagieren sehr stark auf unspezifische Esterase und stark auf β-D-Glucuronidase, β-D-Glactosidase sowie die Enzyme des Citronensäurezyklus, der Glykolyse und der Atmungskette (NAD-ICDH, SDH, ALD, LDH, ADH, GDH, NADH-T-Red, Cyt-Ox).
    Notes: Summary The bulbourethral glands of sexually mature male cats are studied with the light and electron microscope. The parenchyma consists of spacious, sinus-like intraglandular ducts and short, narrow, mostly unbranched tubular endpieces. The gland has no complete connective tissue capsule, consequently some of the peripheral tubules are situated directly in between the fibers of the surrounding bulboglandularis muscle. The endpieces and the sinus of the intraglandular ducts are lined by a simple columnar epithelium, whereas the folds of the ducts are generally covered by a low pseudostratified epithelium. The secretory surface of the cells is increased by intercellular canaliculi which communicate with the gland lumen. These canaliculi are identified on the light microscopic level by their strong 5′-nucleotidase activity. Furthermore widened intercellular spaces (approximately 1,5 μ in diameter) filled with slender, interdigitating cytoplasmic processes extend from the basal lamina to the apical junctional complexes. The luminal cell pole exhibits some short microvilli and forms irregularly shaped, glycogen containing protrusions. Within the cytoplasm of the gland cells numerous spherical mitochondria, some dense bodies, a typical Golgi apparatus, free ribosomes and a poorly developed endoplasmic reticulum are to be observed. Secretory granules which can be grouped into three types on the basis of their electron density occur in the supranuclear regions of most of the cells. According to histochemical tests all granules contain a periodate reactive sialomucin and some of them also sulfate groups. The glandular parenchyma is site of an exceptionally strong unspecific esterase activity and is rich in β-D-glucuronidase, β-D-glactosidase, aldolase, α-glycerophosphate dehydrogenase, lactate dehydrogenase, alcohol dehydrogenase, NAD-dependent isocitrate dehydrogenase, succinate dehydrogenase and cytochrome oxydase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00335273
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