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  • 11
    ISSN: 1432-1106
    Keywords: Postnatal development ; Geniculocortical projection ; Laminar field potential ; HRP ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using laminar field potential analysis, we examined responses elicited by both photic and optic nerve stimulations in 30 kittens of 0–65 days of age and in three adult cats. In adult cats, the response in the visual cortex on optic nerve stimulation is a wave complex which consists mainly of surface positive-depth negative (sP-dN) potentials. By contrast, the response in neonates consists of two surface negative — depth positive (sN-dP) waves. In 2 weeks, preceding the sN-dP waves, an sP-dN wave appears. As age increases, the sP-dN wave becomes of higher voltage and the sN-dP waves become of lower voltage. Thus, the configuration of the response resembles that of adult cats in 3–4 weeks. Both photic and optic nerve stimulations elicit responses of the same configuration in the same area. The extent of the responsive area is exactly the same at any age as in adult cats. Using the orthograde HRP method, we examined terminals of the geniculocortical afferent in 23 kittens of 0–43 days of age. The density of labeled terminals in layer I is much higher in kittens before 1 week of age (n = 8) than in kittens after 1 month of age (n = 5), whereas the density of labeled terminals in layer IV is higher in the older kittens than in the younger kittens. These electrophysiological and morphological changes are correlated in reference to the maturation of the neuronal circuit in the visual cortex.
    Type of Medium: Electronic Resource
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  • 12
    ISSN: 1432-1106
    Keywords: Pallidum ; Cerebellar nuclei ; Thalamus ; Monkey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Thalamic projections of the pallidum and the deep cerebellar nuclei were studied by unitary recordings as well as field potential analysis in the thalamus of squirrel monkeys (Saimiri sciureus) under sodium pentobarbital anesthesia. Stimulation of the pallidum produced a positive field potential preceded by incoming afferent fiber volleys in the thalamus. Spontaneous discharges of thalamic neurons were suppressed during this positive potential, and intracellular recordings from the thalamic neurons revealed that the time course of this field potential corresponded to that of the hyperpolarizing potential. The hyperpolarization was presumed to be a monosynaptic inhibitory postsynaptic potential by the short synaptic delay (about 0.5–0.7 ms) and responsiveness to high frequency stimulation (over 150 Hz). The positive field potential on stimulation of the external pallidal segment was distributed in L.po (VA) and the reticular thalamic nucleus around L.po, whereas that on stimulation of the internal segment was in V.o.a (the anterior basal part of VL) and in Z.o (upper part of VL). The projection of the external segment appeared to be less dense than that of the internal segment. The projection of deep cerebellar nuclei was situated in V.o.a, V.o.p (posterior part of basal part of VL), V.o.i (VLm), the intralaminar nucleus (CL), and some part of V. im (the rostral part of VPLo). Projections of the interpositus and dentate nuclei were distributed in a more anterior part than those of the fastigial nucleus. A certain topographical arrangement of the projections of these three nuclei was found in V.o.p, V.o.i and V.im. No significant overlap was detected between projections of the pallidum and the deep cerebellar nuclei within the thalamus.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 56 (1984), S. 12-22 
    ISSN: 1432-1106
    Keywords: Taste ; Tongue ; Amygdala ; Neural activity ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The responses of 80 amygdaloid neurons to the four basic taste (sucrose, NaCl, HCl and quinine hydrochloride), thermal (5° C, 20° C and 40° C) and tactile (brushing) stimuli applied to the anterior part of the tongue were recorded in anesthetized rats. About 90% of the taste-sensitive amygdaloid neurons responded to thermal and/or tactile stimulations of the tongue as well, and some of them showed convergent responses to tactile stimulation of various parts of the body and to acoustic stimulation. Most (86%) amygdaloid taste-sensitive neurons showed a phasic pattern of excitatory response lasting 1–2 s after onset of stimulation with the broad breadth of tuning to the four taste stimuli. About 35% of the neurons showed monotonic increasing responses with increasing NaCl concentration. The rest of the neurons showed complex intensity-response function. The amygdaloid neurons could be grouped into classes based on their best responsive stimulus, and the response profiles of those neurons showed relative regularity when the four stimuli were hedonically ordered from most to least preferred (i.e., sucrose, NaCl, HCl, quinine). Across-neuron correlations between magnitudes of responses to pairs of the four basic taste stimuli have suggested a tendency that taste information is processed in a hedonic dimension in the amygdala. The neurons in the central (Ce) nucleus showed some differential taste responses from those in other amygdaloid nuclei, i.e., about half of the Ce neurons showed tonic responses, and the across-neuron correlation coefficients in the Ce neurons were much higher than those in the non-Ce neurons.
    Type of Medium: Electronic Resource
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  • 14
    ISSN: 1432-1106
    Keywords: Rats ; Gustatory cortex ; Amygdala ; Taste ; Conditioned taste aversion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The functional interconnections between the cortical gustatory area (CGA) and the amygdala were examined by electrophysiological and behavioral experiments in rats. The cortical neurons responsive to taste stimuli applied to the anterior part of the tongue were located in the Vth layer of the agranular insular cortex. Of a total of 27 cortical neurons recorded, 10 showed facilitatory and/or inhibitory responses with the mean onset latency of about 20 msec to electrical stimulation of the ipsilateral amygdala. On the other hand, of 18 amygdaloid neurons responsive to taste stimuli, 13 showed facilitatory and/or inhibitory responses to electrical shocks to the ipsilateral CGA, with a mean latency of about 16 ms. No cortical and amygdaloid neurons sampled responded antidromically to the electrical stimulation. These results suggest the existence of mutual polysynaptic fiber connections between the CGA and the amygdala. The behavioral experiment was performed by means of a conditioned taste aversion (CTA) technique. After acquisition of CTA to sucrose solution by pairing it with an i.p. injection of LiCl which produces sickness, bilateral small knife cuts between the CGA and the amygdala in the perirhinal region disrupted retention of CTA. Thus, these interconnections may play some role in association of taste-related cognitive processes with feeding behavior.
    Type of Medium: Electronic Resource
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  • 15
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Two types of monoamine-containing subependymal cells were studied microspectrofluorometrically and electron microscopically. Microspectrofluorometric analyzes showed that yellow fluorescent cells contained 5HT and blue-green fluorescent cells dopamine (DA). These two types of fluorescent cells could be recognized also in a thin section (about 250 nm thick) mounted on a reference grid. Electron microscopy of the same section revealed that electron dense granules in the 5HT-containing cells are larger (80–140 nm) in size than those in the DA-containing cells (60–100 nm).
    Type of Medium: Electronic Resource
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  • 16
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary C33k polypeptide, which is a cytosol polypeptide with molecular weight of 33000 and approximate pI value of 7.5, has three common electrophoretic phenotypes and is an abundant polypeptide in peripheral blood lymphocytes, fibroblasts and red blood cells. Family and population studies indicate that the three phenotypes of C33k polypeptide are determined by two common alleles at a single autosomal locus. The gene frequencies of the two common alleles were 0.642 and 0.358, respectively, in a Japanese population. Since esterase D has a subunit size and gene frequencies similar to those of C33k polypeptide, the phenotypes of C33k polypeptide and esterase D were compared in 18 families totaling 72 members. Perfect concordance of the phenotypes between C33k polypeptide and esterase D was observed in all 72 members. In addition, a gene dosage effect on the expression of the phenotype of C33k polypeptide was observed in the red blood cell lysate from a patient with partial 13q trisomy who was reported to have two doses of EsD 1 and one dose of EsD 2. These data indicate that the polymorphic C33k polypeptide is esterase D, which is assigned to chromosome 13q14. This finding is useful for the detection of proteins coding for by chromosome 13q14-linked genes in the studies on human gene mapping using somatic hybrid cell lines and two-D gel electrophoresis.
    Type of Medium: Electronic Resource
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  • 17
    ISSN: 1432-2013
    Keywords: Skinned muscle fibres, calcium activation of ; Skinned muscle fibres, effect of Mg-ATP ; Muscle stiffness, sarcomere length dependence ; Muscle force ; sarcomere length dependence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract 1. Skinned fibres prepared from semitendinosus muscle of the frog (Rana temporaria) by a modified Natori's method were suspended in ATP-salt solution (pCa 5, pH 6.7, 3°C). Isometric tension was studied as a function of sarcomere length (determined by laser diffraction) and stiffness was measured by recording tension changes in response to quick changes in length performed within 0.5 ms during Ca2+ activated contractions. 2. There was a sigmoidal relationship between contractile tension or stiffness and pCa. The threshold Ca ion concentration was 5×10−7 M at a sarcomere length of 2.2 μm and a little lower at larger sarcomere lengths (as also described by Endo 1972). At all sarcomere lengths peak tension was reached at about 10−5 M Ca2+. 3. The skinned fibres produced maximum tension at sarcomere lengths of 2.0–2.3 μm. With a further increase in sarcomere length, contractile tension decreased. The relation between tension and sarcomere length was linear up to 3.2 μm above which value the relationship ‘tailed’. 4. Quick releases in the range of 0.1–0.5%L 0 applied during Ca2+ activation produced an immediate elastic fall in tension in phase with the length change followed by a quick recovery phase completed within about 10 ms. Conversely, a quick stretch produced an elastic increase followed by a rapid tension decay completed within about 8–10 ms. When the extreme tensions obtained during the length step were plotted versus the size of the length step, a force-extension diagram was obtained corresponding to the T1-curve of Huxley and Simmons (1973) which intercepted the length axis at about −8 nm/half sarcomere at all sarcomere lengths investigated. The slope of the linear portion of the T1-curve was taken to determine immediate stiffness which was proportional to tension when either sarcomere length or Ca2+ ion concentration were varied. 5. In conclusion tension and immediated stiffness are proportional to the extent of actin myosin filament overlap and hence to the number of possible crossbridges between thick and thin filaments. 6. At very low calcium ion concentrations (10−7 M) skinned fibres develop tension and become stiff when the Mg-ATP concentration is lowered (at constant [ATP] total) to values below 10−5 M. Under these conditions a quick release causes a drop in tension which is—as in the case of rigor—not followed by a fast recovery of tension. Again stiffness was independent of the direction and amplitude of quick length changes; but — as in the case of rigor — the stiffness to tension ratio was much higher than in Ca2+ activated contraction.
    Type of Medium: Electronic Resource
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 135 (1980), S. 91-95 
    ISSN: 1432-1076
    Keywords: Histiocytosis X ; Hepatic lipids ; Foam cell
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A case of Letterer-Siwe disease in a thirteen-month-old girl with markedly swollen gums, an enlarged liver, and seborrhoic skin eruptions is reported. She died from pyopneumothorax in spite of treatment with prednisolone and vinblastine. Analysis of hepatic lipids showed that there was remarkable increase in free fatty acid, which is not seen in normal human liver. Cholesterol ester was also accumulated in the liver tissue. However, the concentrations of phospholipids and glycerides were low and lysophospholipid was found. It is assumed that there was increased intracellular lipolysis in the proliferating reticuloendothelial cells.
    Type of Medium: Electronic Resource
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  • 19
    ISSN: 1432-1076
    Keywords: Hypophosphataemic rickets ; 1,25(OH)2D ; 1α-hydroxylase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In 1974, a 2-year-old boy was diagnosed as having X-linked hypophosphataemic rickets (XLH) because of severe rickets and hypophosphataemia. The vitamin D metabolite concentrations, blood and urine chemistry and renal 25-hydroxyvitamin D3 (25 OHD3)-1α-hydroxlase were measured in 1982 (about 2 weeks after withdrawal of medication). 1α-hydroxylase was 392 pg/mg tissue/20 min in the patient, which was high compared with aged-matched controls (69.7±28.5 pg/mg tissue/20 min, mean ±SD, n=7). Our present studies showed that the 1α-hydroxylase activity in the patient with XLH was elevated. Therefore, the normal or low 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) concentrations in XLH patients could be due to accelerated catabolism of 1,25-(OH)2D3 or abnormally regulated 25OHD3-1α-hydroxylase in response to hypophosphataemia, although significantly elevated above that in normal controls.
    Type of Medium: Electronic Resource
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  • 20
    ISSN: 1432-0738
    Keywords: Fenitrothion ; Fenitrooxon ; Acute toxicity ; Phenobarbital ; Adrenalectomy ; Diethyl maleate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of adrenalectomy (Adx), SKF 525-A, phenobarbital (PB), and diethyl maleate (DEM) on the acute toxicity of fenitrothion was investigated in male rats by assessing the degree of plasma cholinesterase activity. PB, 60 mg/kg/day for 3 days, exerted no protective effect on the toxicity of fenitrothion (100 mg/kg, p.o.) given 24 h after the last injection. In adrenalectomized and SKF 525-A-pretreated rats, the toxicity of fenitrothion was lower than that of the controls. Fenitrothion toxicity was increased by administration of DEM (1 ml/kg), which depletes hepatic glutathione (GSH) levels. In vitro, the rates of fenitrothion decomposition and fenitrooxon formation by microsomes were markedly affected by PB, SKF 525-A and Adx. The decomposition of fenitrooxon by the microsomal fraction and GSH-dependent decomposition of fenitrooxon by the soluble fraction were not affected by PB, SKF 525-A and Adx pretreatment. The GSH-dependent decomposition of fenitrothion and fenitrooxon was increased by addition of GSH to the incubation mixture. The present results indicate that the GSH-dependent metabolic pathway plays an important role in the detoxication of fenitrothion.
    Type of Medium: Electronic Resource
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