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H Hilbig

Publications and source records attributed to H Hilbig.

30 records · Page 2Linked to original sources
PubMed1995

On the structure of the pretectal nuclei of the rat: an immunocytochemical and tracer study.

We have studied the distribution of the calcium-binding proteins parvalbumin, calbindin and calretinin, the NADPH diaphorase activity and the morphology of the commissural neurons, revealed by the stereotactic applications of fluorogold in the pretectal complex of the rat. The histochemical differentiation of the pretectal complex shows a complementary pattern of parvalbumin and calbindin containing cells. Only a few of the neurons in the pretectal complex contain calbindin. Calretinin immunoreactivity is scant and diffuse. The NADPH-diaphorase activity is restricted to neurons and terminals in the nucleus of the optic tract and the dorsal terminal nucleus. Due to numerous active fibers which traverse these nuclei they display a reticular appearance. Commissural neurons constitute 20% of the cell number of the pretectal complex and are restricted to the dorsal and lateral terminal nuclei.

Animals↗
PubMed1994

Interlayer neurones in the rat superior colliculus: a tracer study using Dil/Di-ASP.

Five different populations of interlayer neurones (ILNs) can be described after DiI/Di-ASP tracing in rat superior colliculus (SC). All of these labelled neurones preferentially lay in the rostro-medial part of the SC. Most of them are located in the stratum opticum and in the stratum griseum superficiale. Our results indicate that ILNs represent a minority of neurones in the superficial layers but may constitute a substantial population of neurones in the stratum opticum connecting the visual and the multimodal collicular layers.

Animals↗
PubMed1994

Morphological analyses of NADPH-diaphorase/nitric oxide synthase positive structures in human visual cortex.

Human visual cortex was studied using NADPH-diaphorase histochemistry and nitric oxide synthase immunohistochemistry. Large, strongly stained, sparsely spined non-pyramidal cells (average soma diameter: 16 x 16 microns) occur in layers II-VI, but are commonest in layers II-III. Small weakly stained multipolar cells (average soma diameter 3.6 x 4 microns, stellate like cells) in layers II-VI are concentrated in layer IV of areas 17 and 18. The density of these cells, measured with a computer assisted microscopy system is less in area 18 than 17. Large, strongly stained, predominantly horizontal cells (average soma diameter 12 x 19 microns) are localized in the underlying white matter. Axons of the large, strongly NADPH-diaphorase positive cells are thin and unbranched with fine boutons. These axons ascend to layer I. The large, strongly stained cells in layers II-VI we identify as Martinotti neurons. In layer I parallel unbranched positive fibres with some fine boutons run horizontally and build dense axonal plexuses together with the axons of Martinotti neurons. Axons of presumed extrinsic origin are morphologically different from NADPH-diaphorase positive intrinsic fibres. They show thick varicosities running in different directions and forming a network in layers III-VI. Basket like formations of these fibres were frequently observed in layers IV, V and VI. Other fibres seem to innervate blood vessels. Nitric oxide synthase was also demonstrated immunohistochemically by a polyclonal rabbit nitric oxide synthase antiserum. The morphology and distribution of the immunostained cells correspond with those seen with NADPH-diaphorase histochemistry. Double labelling experiments confirm the colocalization of NADPH-diaphorase and nitric oxide synthase in all demonstrated cells. Immunohistochemical demonstration of glial fibrillary acidic protein has shown that astrocytes are not involved in the NADPH-diaphorase/NOS system in the human visual cortex.

Aged↗
PubMed1994

Aberrant visual pathways in microphthalmic mice.

We report results obtained in the microphthalmic strain of mice 944. Heterozygotes appear normal, but they produce litters in which typically between 2 and 5 offspring exhibit microphthalmia. As a result these animals are blind. Our investigations using the fluorescent tracer DiI show that in microphthalmic mice there is a small compensation for the missing retinal input by terminals or axon collaterals originating in the somatosensory thalamus. These morphological findings agree with somatosensory responses recorded in the visual cortex (EEG recordings).

Animals↗
PubMed1991

[Neurons in the visual cortex of Microtus brandti].

Neurons were described in the visual Cortex of Microtus brandti, a Mongolian harmful rodent living in day-activity. We find following types of neurons in our Golgi-material: 1. spiny neurons: pyramidal and stellate neurons. 2. smooth or sparsely spined neurons: smooth, large neurons, sparsely spined small neurons with descending axons, sparsely spined neurons with ascending axons. Double-bouquet-, chandelier and neuroglioforme cells are not impregnated. There are no bipolare neurons (Martinotti cells) among the neurons with ascending axons. The small, sparsely spined neurons are not only in lamina IV - like in other species - but they can also be found in laminae II to IV. Their distribution of spines on the distal parts of dendrites seems to be characteristical for rodents. The lamination of the visual cortex of Microtus brandti is the same like in the rat. All cells are of large size in relation to the body mass of the animal.

Animals↗
PubMed1991

[The structure of the superior colliculus in the microphthalmic mouse strain 944].

The structure of the superior Colliculus (CS) in congenitally blind mice was compared with that in healthy control mice. Thus Nissl staining and degeneration experiments were done resulting in differences in the Stratum opticum (SO) of the CS between microphthalmic and control mice. In microphthalmic mice the volume of SO decreases in 14% and packing density of neurons increases in 20% in comparison with controls. Terminal degeneration after lesion of the ipsilateral visual cortex is seen in the surface laminae only. This connection seems independent of visual signals.

Animals↗
PubMed1990

Development of visual callosal projection in the microphthalmic stain of mice 944.

The strain of mice 944 produces a recessive microphthalmy. The microphthalmic mice were compared with phenotypically healthy animals of the same litter and with 944-mice bilaterally enucleated at 1. postnatal day (pd). Comparison was done at the 5., 10., 15. and 20. pd after lesion of the right visual cortex 24 hours before. Therefore Nissl- and Fink-Heimer-series were prepared. The results are the following: At 20. pd microphthalmic mice show both retrograde and anterograde degeneration after lesion. Enucleated and control mice produce destroyed fibres only. This evidence of callosal projection in visual cortex is possible exclusive at pd 20 with satisfying results. The neurons of laminae II and III project in the animals with a normal visus exactly to the contralateral 17/18a borderline. Enucleated mice show in area 18a two or three stripes more reaching laterally. Microphthalmic mice have terminals in both area 17 and 18a.

Animals↗
PubMed1989

[Comparison of relay neurons in the lateral geniculate body of normal, bilaterally enucleated and congenitally blind strain 944 mice during ontogenesis].

Mice with normal visus, bilaterally enucleated and congenitally blind mice of the strain 944 were used to determine following parameters in the CGLd on day 5, 10, 15 and 20 post natum (Golgi impregnation): size of neurons (perikarya, size of dendritic domains DF), structure of dendrites (number of dendrites FDE, branching points VZP, distribution of dendritic density in relation to the perikaryon Is, number of primary dendrites). After Nissl staining the following parameters were investigated: volume of the CGLd, packing density and total number of cells in the CGLd. The differences between the three investigated groups of animals increase in changing amounts during the ontogenesis. The caudal part of the CGLd is altered mostly by the lacking optic events. Suppression of visual events during the normal ontogenesis caused by genetic defect or enucleation attacks the same structures of the neuron.

Aging↗
PubMed1989

[Volumetric and golgi studies of the corpus geniculatum laterale pars dorsalis of Alticola stoliczkanus barakshin and Alticola argentatus semicanus].

The dorsal lateral geniculate bodies (dLGB) in Alticola stoliczkanus barakshin, the Gobi-Altai-Mountain vole, and in Alticola argentatus semicanus, the silver grey mountain vole, and investigated using the nissl- and the golgi method. The geniculo-cortico-relay neurons (GCR neurons) of both species have 5 primary dendrites (D1), a dendritic field of about 100 micron, about 17 free dendritic distal parts (FDE), 10 branching points (VZP) and a average of the perikaryon of 10 micron. All tufted neurons are small and topographically distinctly localised. The dLGB's volume of Alticola stoczkanus, barakshin is 0.16 mm3, the dLGB's volume of Alticola argentatus semicanus is 0.23 mm3.

Animals↗
PubMed1986

[The microphthalmic 944 strain of mice as a model for ontogenesis studies of the visual system. Volumetric and Golgi studies on the lateral geniculate body in the pars dorsalis].

We investigated a strain of mice with recessive microphthalmy. The mutant mice were compared with phänotypically healthy animals of the same litter using following parameters: daily pattern of motor activity, EEG pattern of the visual cortex, relative brain weight, volume of the Corpus geniculatum laterale pars dorsalis (CGLd), packing density and total number of cells in the CGLd, size of neurons (perikarya, size of dendritic domains DF), structure of dendrites (number of dendrites, branching points VZP, distribution of dendritic density in relation to the perikaryon Is). Neuromorphological parameters were investigated at postnatal days (pd) 5, 10, 15 and 20. At pd 5 we did not find differences between mutant and phänotypically healthy animals. At pd 20 the CGLd's volume of the microphthalmic mice decreased by 30% and the packing density of neurons increased by 20% compared with the healthy animals of the same litter. We observed striking changes in VZP, Is and DF of the dendritic tree. The most stable parameter is the number of the primary dendrites which is between 4 and 5.

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