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W Schober

Publications and source records attributed to W Schober.

At least 55 records · Page 3Linked to original sources
PubMed1982

Identification of geniculo-tectal relay neurons in the rat's ventral lateral geniculate nucleus.

In the rat's ventral lateral geniculate nucleus (vLGN), geniculo-tectal relay neurons (GTR-neurons) could be identified by the retrograde transport of horseradish peroxidase (HRP) after injection in the superior colliculus (SC). GTR-neurons correspond to class III cells described by Brauer and Schober (1973) in Golgi preparations of the rat's LGN. The distribution of GTR-neurons is restricted to the lateral subnucleus of vLGN. According to Swanson et al. (1974), the axons of these cells terminate in lower Stratum griseum superficiale and in Stratum opticum, Stratum griseum intermedium and Stratum album intermedium of SC. The GTR-neurons are characterized by very thick and long proximal dendritic segments which have a smooth surface. Dendrites branch preponderantly in their distal regions and only in this part form many multiform protrusions. There is some evidence that retinal axons terminate on these dendritic surface structures. The supposed differences in the afferent patterns between GTR-neurons in the vLGN and geniculo-cortical relay neurons in the dorsal lateral geniculate nucleus are discussed.

Animals↗
PubMed1981

[Morphological differentiation in connection with the functional specialization of the mammalian visual system (author's transl)].

In the mammals there are two visual pathways: 1. retino-geniculo-cortical (as a rule area 17) and 2. retino-colliculo-thalamo-(pulvino-) cortical (mainly areas 18 and 19). In connection with the visual specialization the first pathway only shows on the subcortical level (dorsal lateral geniculate nucleus) and on the cortical level (area 17) morphological differentiations. In contrast, the differentiation of parts of the second pathway (pulvinar complex and associative cortex) is the expression of a higher evolution of this system. In the dLGN the input-zones of the ipsi- and contralateral eye are separated more and more. This becomes visible by a cytoarchitectonic lamination of the dLGN. In area 17 layer IV is--in connection with the specialization--increasingly divided in sublayers where the fibers of the X- and Y-system terminate separately.

Animals↗
PubMed1980

[Urological complications in patients with multiple sclerosis (author's transl)].

63 patients with multiple sclerosis underwent urodynamic evaluation. Hyperreflexia of the bladder was found in 64% and areflexia in 8%. Hypertrophy or sclerosis of the bladder neck (internal sphincter) was detected in 27% of the patients and a spastic external sphincter (dyssynergia) was encountered in 57%. 16 patients were admitted for surgery: 9 for TUR of the bladder neck, 5 for percutaneous selective sacral nerve block, 2 for ileal diversion, 2 for prolonged bladder distension and 1 for nephrectomy for staghorn calculi of the renal pelvis. Highly effective conservative therapy is available in the form of Lioresal for treatment of the hyperactive detrusor muscle and Dibenzyran - an alpha-adrenergic blocking agent - to relieve bladder neck spasticity.

Adolescent↗
PubMed1979

[Localization of thalamic afferents in the regio cingularis of the rat].

After lesioning the nucleus mediodorsalis and the nucleus anteromedialis thalami, where from specific afferents project to the cingulate cortex, we confirm signs of transneuronal degeneratiopn at lamina-V-pyramidal neurons of the cingulate cortex. By the GOLGI-KOPSCH-method operated animals show statistically significant decrease of dendritic spines at the apical main dendrites of lamina-V-pyramidal cells compared with the controls. The average spine-decrease along 300 micrometer length of the apical main dendrite amounts to 16%. Maximal spine-decrease is present at the central part of the apical main dendrite: 23% within a 50-micrometer-segment of this dendrite. This central dendritic part passes through the lamina III of the cingulate cortex. By the FINK-HEIMER-method degeneration particles are preferentially dispersed in laminae I, III and lower layers. The results give evidence for a more precise neuronal localization of the specific afferent terminations in this region.

Afferent Pathways↗
PubMed1978

[The catecholaminergic connections of the visual system of the albino rat (author's transl)].

By using the glyoxylic acid method of DE LA Torre and Surgeon (1976), occurrence, distribution and origin of catecholamines were investigated in the visual system of the albino rat. A dense network of green fluorescent terminals and preterminals could be detected in the dLGN. The spreading of terminals of catecholaminergic fibres had been observed in laminae I and II of the visual cortex. Investigation of lamina I with the Golgi-Kopsch method showed axons the thickness of which was below 1 micron, and with varicosities with a distance of approximately 3.5 micron, having a diameter of 2 to 4 micron. These axons might be identical with the fluorescent-histochemically represented terminals. Taking into account the course of catecholaminergic axons it can be concluded that the pyramidal cells of the neocortex, the spiny dendrites of which are heavily branched in the lamina I, are affected. After application of horseradish-peroxidase in the dLGN labelled cells have been found in the locus coeruleus (A6) only. After application of the enzyme in the visual cortex, labelled cells have been observed in the nuclei A 6 and A2. The pathway of catecholaminergic axons from the nucleus of origin to the terminal regions was investigated using the "false transmitter" 6-OH-DA. The results can be seen in a diagram.

Animals↗
PubMed1978

[A study of cerebral autonomic attacks with special reference to sympathetic hyperactivity (author's transl)].

The present paper deals with cerebral autonomic attacks, in particular the ergotropic forms. The clinical symptoms associated with these forms of attacks are described. A multichannel recorder was used for the synchronous recording of various neurophysiological parameters such as ECG, pulse form and psychogalvanic reflex. It is shown that the polycrotic pulse form is characteristic hyperactivity of the sympathetic nervous system with the hypertonic, as well as the hypotonic forms of manifestation. Cases with epileptic fits and those with non-epileptic forms of attacks, as well as "mixed forms" are discussed. The diagnostic significance of these investigations is pointed out and the therapeutic consequences hinted at.

Adult↗
PubMed1978

Phylogenetical changes and functional specializations in the dorsal lateral geniculate nucleus (dLGN) of mammals.

Depending on their visual specialization and their place in the zoological system the mammalian species show some peculiarities in the morphology of the dorsal lateral geniculate nucleus (dLGN). The lamination of dLGN can be find in mammals with a highly developed visual system and a proportionally big part of ipsilaterally projecting retinogeniculate fibres. Number and sequence of ipsi- and contralaterally innervated laminae varies between species of different taxonomical categories. Hence these features depend on phylogenetical trends which could traced back to the beginning of the "mammalian radiation" in the cretaceous period and the earliest tertiary. Ancestral conditions may be found in mammals with an unlaminated dLGN and a medially located ipsilaterally innervated part. It may be registrated that a cytoarchitectonical separation of laminae (concerning the ipsi- and contralateral innervation) is the secondary step after fibre anatomical separation. The most primitive status may be realized in mammals having a zone of mixed ipsi- and contralateral fibre input. Some conclusions are made with regard to the suitability of lab mammals for generalization of results in the dLGN morphology.

Animals↗
PubMed1978

[Projection of different ganglion cell classes in the albino rat retina. A study using horseradish peroxidase].

In order to demonstrate the central projections of the different ganglion cell classes in the albino rat retina horseradish-peroxidase was injected into the superior colliculus (CS) and into the lateral geniculate nucleus (Cgl). The study presents the following results: a) Injection into the CS: Labelled cells are only in the contralateral retina. Topistically, the retino-collicular projection is in good agreement with the findings of physiological methods. The nasal half of the retina projects mainly to the posterior part and the superior half to the lataral part of the CS. Taking into consideration our cell-size-classification among 500 labelled cells we found 63% of the small group (7...10 micrometer soma diameter), 35% of the medium-sized (11...14 micrometer) and only 2% of the large group (15...23 micrometer). The small cells (W-system)project mainly, but not alone and not exclusively to the CS. b) Injection into the Cgl: In the ipsilateral retina we found a few labelled cells in the superior, temporal region. Contralateral--as after CS-injection--only half of ganglion cells is labelled. The quantitative analysis of 500 labelled cells indicates: 32% belong to hte small group, 51% to the medium-sized and 17% to the large group. There are fibers of all three classes, but in the majority those of the medium-sized class terminating in the Cgl. It is discussed whether these results allow a comparison of the size classes with the W-, X- and Y-system. Our findings show that there is no clear agreement between cell-size and projection site as demonstrated in cats. There is a large overlapping of the cell classes with respect to their central projection. We found that with increasing soma-diameter the ganglion cells project more and more to the Cgl. It is known that in the Golgi-picture cells with different soma diameter are of the same neuron type. Therefore, a morphological comparison of the ganglion cells of the rat with the W-, X- and Y-system is only ingenious taking into consideration also the dendritic structure.

Animals↗
PubMed1977

[Polygraphic studies on ergotropic and trophotropic attacks (a contribution to the question of hyperactivity of the central sympathetic system) (author's transl)].

A multi-channel recorder has been employed for the simultaneous recording of various neuro-physiological parameters such as EEG, respiration, tremor, ECG, PGR, pulse-tracing and EMG. The present pilot study shows that of all parameters only EEG, pulse-form, PGR and EMG are of high diagnostic value. The importance of these records, in conjunction with neuro-clinical findings, in the differential diagnosis of ergotropic and trophotropic forms of attacks, as well as their differentiation from epileptic fits is pointed out. The pulse-form described in detail, particularly the characteristics of the "ergotropic pulse-form". The special advantage of the present method lies in its non-aggressive nature. Operational details are given in order to facilitate comparisons.

Adult↗
PubMed1977

Cholinergic transmission in subcortical and cortical visual centers of rats: no evidence for the involvement of primary optic system.

The effect of unilateral enucleation, ablation of the visual cortex or coagulation of the lateral geniculate nucleus (LGN) upon the activity of choline acetyltransferase (ChAc) and acetylcholinesterase (AChE) in different structures of the visual system of albino rats was studied. The localization and extent of the degeneration pattern were followed up by histological silver degeneration methods. Afferents from the retina project mainly contralaterally to the dorsal and ventral LGN, the pretectal region and the superior colliculus. Afferent fibres from the dorsal LGN enter the visual cortex in area 17 only. Neurons of this area project back ipsilaterally to the LGN and the superior colliculus (SC). No significant decrease in the activity of the cholinergic marker enzyme choline acetyltransferase could be observed under any of the experimental conditions; there was rather a tendency to increased activity in the subcortical centres. AChE as a less specific marker also exhibited no gross changes in activity in the lesioned animals. The results add more direct proof to pharmacological and physiological evidence that ACh is not involved in the synaptic transmission of the direct optic projections in rats, either at the subcortical or at the cortical level.

Acetylcholinesterase↗
PubMed1977

[Morpho-histochemical characterization of the connections between the dorsal part of the lateral geniculate nucleus (LGN) and the brain stem of albino rats) (author's transl)].

After selective application of horseradish peroxidase (HRP) into the dorsal part of the lateral geniculate nucleus (LGN) of the albino rat, cells were labelled through the retrograde transport of the enzyme in the following nuclei of the brain stem: 1. Ncl. raphes linearis, 2. Nel, raphes centralis, 3. Ncl. raphes dorsalis, 4. Ncl. ventralis rostralis lemnisci lateralis, 5. Ncl. coeruleus. Using the glyoxylic acid method to demonstrate biogenic amines we could find serotonine in following areas of the brain stem: 1. region B 7 (Ncl. raphes dorsalis) positive cells; 2. region B 8 (Ncl. raphes centralis) mainly positive fibres; 3. region B 9 (dorsal of the Lemniscus medialis) a few positive cells; 4. mesencephalic reticular formation (Area cuneiformis) network-like fibre structures; 5. dorsal LGN, in the lateral part mildly fluorescing fibres, the remaining LGN showing diffuse fluorescence, 6. Substantia nigra, fluorescing cells. The monosynaptic connections between the mesencephalic raphe nuclei and the dorsal part of the LGN, demonstrated by means of the HRP-method, are characterized as being serotoninergic with the help of fluorescence histochemistry. The character of the transmitter of these connections is compared with results of biochemical and pharmacological investigations.

Animals↗
PubMed1977

[Retinal ganglion cells of the albino rat: a qualitative and quantitative study].

Ganglion cells were investigated qualitatively and quantitatively in whole mount preparations of the albino rat retina, stained with cresylviolet. Cells of different size are distributed in different density over the retina, mainly arranged radially. The ganglion cell density varies between about 1200/mm2 at the edge of the retina and 5000/mm2 in the central area, centered about 1,5--2 mm away from the optic disc in the upper temporal quandrant. The mean soma diameter of the ganglion cells ranged from 7--23 micron. Based upon soma diameter histograms with regard to the eccentricities of the area centralis, ganglion cells were classified into three groups: small (7--10 micrometer diameter) mediumsized (11--14 micrometer) and large (15--23 micrometer). Relative frequencies of these groups were 53, 40 and 7% respectively. In the area centralis is the highest density of small cells. Here the relative frequencies were 62, 34 and 4% respectively. The diameter of the retina runs to 8 mm and the area to more than 40 mm2. In 2 retina the total number of ganglion cells were about 108000 and 111000 respectively.

Animals↗