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E Winkelmann

Publications and source records attributed to E Winkelmann.

At least 37 records · Page 2Linked to original sources
PubMed1990

Ultrastructure of neurons and their synaptic contacts in the medial septal nucleus of the rat.

The medial septal nucleus of non-experimentally treated albino rats was investigated electron microscopically. According to former light microscopical findings most of the dendrites in this region are spineless but conspicuously varicose. Besides a striking diminution of the packing density of neurotubules inside the varicosities--compared with the narrow portions of varicose dendrites--some organelles like multivesicular bodies, lamellated bodies and cisterns of the smooth endoplasmic reticulum were found to be characteristic of them. Large neuronal somata rich in RER with a broad rim of cytoplasm around the nucleus and numerous lipofuscin-like granules occur. But there are numerous small cells exhibiting a narrow rim of cytoplasm and pourly developed RER, too. At least six classes of synaptic junctions can be distinguished, three of the asymmetric and three of the symmetric type. Most of axo-somatic contacts are of the symmetric type, at the dendrites asymmetric contacts dominate. Presynaptic profiles with large dense-core vesicles form symmetrical contacts with varicose and non-varicose dendritic profiles.

Animals↗
PubMed1989

A Golgi deimpregnation study of neurons in the rhesus monkey visual cortex (areas 17 and 18).

The morphological features of 298 neurons impregnated according to Golgi-Kopsch in areas 17 and 18 of Macaca mulatta were analyzed, and the same neurons were deimpregnated to visualize structural details of the somata in different types of neurons. The following cell types were investigated: Pyramidal and pyramid-like cells, spiny stellate cells, double bouquet cells, bipolar cells, chandelier cells, neurogliaform cells, basket and related cells. This procedure allows the evaluation of the nuclear-cytoplasmic proportion and the position of the nucleus besides shape and size of the cell body. Pyramidal and pyramid-like cells (N = 43), spiny stellate cells (N = 26), basket and related cells (N = 126) are variable in these features. A positive correlation between soma size and width of the cytoplasm is found in pyramidal, pyramid-like cells and spiny stellate cells. With the exception of some large somata in both these types of neurons the nucleus is found in a central position. Double bouquet cells (N = 6), bipolar cells (N = 13) and chandelier cells (N = 11) exhibit small cytoplasmic rims and centrally located nuclei. The small somata of neurogliaform cells (N = 37), however, and the small to very large somata of basket and related cells show broad cytoplasmic portions surrounding the eccentrically located nuclei. These findings allow the identification of different neuronal types in Nissl-stained sections on the basis of these soma features. This is a prerequisite for further detailed quantitative studies on the laminar distribution of different neuronal types in the visual cortex of the monkey.

Animals↗
PubMed1989

[The classification of neurons in the corpus geniculatum laterale pars ventralis of the albino rat: a Golgi-Kopsch study].

Neurons in the ventral lateral geniculate nucleus of 120 rats of a wistar strain were investigated with the Golgi Kopsch technique. Various features, such as size of neurons, their dendritic fine structure and their localization inside the nucleus were used to find new aspects for the classification of vLGN neurons except geniculo tectal relay neurons (GTR neurons). The results of our detailed investigation are in accordance with the classification given by Brauer et al. (1984). The dendrites show different morphological surface specializations, as there are smooth and varicose dendrites besides the spiny ones. Medium-sized neurons are most variable in their dendritic structure. It can be assumed that they represent a heterogenous group. The density of spines in the neurons investigated is much lower than in GTR neurons.

Animals↗
PubMed1989

Shape and size of synaptic vesicles in different types of presynaptic profiles in the medial septal nucleus of the rat.

Long and short axis diameters of synaptic vesicles were obtained from 6 classes of presynaptic boutons found in the medial septal nucleus (MS) of the rat. The variability of vesicle size and shape was documented in diagrams and discussed with regard to their suitability as criteria of classification and their functional significance. The variability in shape, but not in size, of vesicles in synapses of Gray's type I is lower than of those in Gray's type II synapses.

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↗
PubMed1988

Topographic differences in retinal axons in the dorsal lateral geniculate nucleus of the rat: a quantitative reexamination using anterograde transport of horseradish peroxidase.

Retinal endings in the dorsal lateral geniculate nucleus (dLGN) of the rat were visualized by anterogradely transported horseradish peroxidase following injections in the optic tract. The morphological findings confirm the two types of retinal axons previously suggested by Golgi investigations. In the caudal third of the dLGN type 2b axons, with small dense clusters of boutons, are the only representatives of retinal fibres seen. In the rostral two thirds they are intermingled with the larger type 2a terminals, but tend to accumulate laterally, adjacent to the optic tract. This study supports the concept that large retinal ganglion cells probably give rise to 2a axons that may represent a Y-like channel, whereas 2b axons are derived from small ganglion cells, and may relay a W-like pathway.

Animals↗
PubMed1988

New prodrugs of acyclic nucleosides with antiviral activity.

More than 130 acyclic purine and pyrimidine nucleoside derivatives have been synthesized. Structure-activity relationships among a selected group of 6- and 9-substituted guanine derivatives will be discussed. By introduction of secondary aliphatic (e.g. isopropyl or secondary butyl) ether groups into acyclic nucleosides such as aciclovir and ganciclovir new lipophilic prodrugs with modified physical and improved pharmacokinetic properties have been obtained. Several compounds with isopropylether groups in the side-chain and/or in the 6-position (among these the 6-deoxy derivative Hoe 602) of the purine moiety displayed excellent antiviral activity when tested in vivo against herpes simplex virus type 1 infection in mice.

Acyclovir↗
PubMed1988

Neurons in the basal forebrain complex of the rat: a Golgi study.

Several types of neurons are coexistent in the basal forebrain nuclear complex of the rat. In the medial septum and vertical limb of the diagonal band 3 classes of neurons occur which are characterized by varicose dendrites. In the horizontal limb of the diagonal band neurons with smooth dendrites and those with varicose dendrites are intermingled. We found 3 classes of neurons in the nucleus preopticus magnocellularis. A giant type with smooth and varicose dendrites occurs in this nucleus, but also in the substantia innominata. In the substantia innominata-nucleus basalis complex 4 classes of neurons with varicose dendrites and 2 classes with spiny dendrites have been observed. Our findings suggest that the nucleus of the vertical limb of the diagonal band forms a unit with the nucleus septi medialis, but is separated from the nucleus of the horizontal limb of the diagonal band by different neuronal composition. The nucleus preopticus magnocellularis is a separate nuclear structure characterized by a content of neurons different from those in the horizontal limb of the diagonal band and in most components also from the substantia innominata-nucleus basalis complex. There is some evidence that the cholinergic neurons have to be searched among those with varicose dendrites.

Animals↗
PubMed1987

Cells with varicose dendrites: a characteristic type of neurons in Golgi preparations of the rat cholinergic basal forebrain nuclei.

Golgi preparations reveal that in the basal forebrain nuclei composed of medial septal nucleus, diagonal band, nucleus preopticus magnocellularis and substantia innominata including nucleus basalis magnocellularis of Meynert, the most frequently impregnated type of neuron is medium to large sized with long smooth or sparsely spined varicose dendrites. Some indications implying the cholinergic nature of those cells are discussed.

Animals↗
PubMed1987

Antimalarial and anticoccidial activity of 3-aryl-7-chloro-3,4-dihydroacridine-1,9-(2H,10H)-diones. 1-Imines, 1-amines, 1-oximes, 1-hydrazones and related compounds.

Out of more than 130 synthesized derivatives of floxacrine and of 10-deoxyfloxacrine, such as 3-(4-trifluoromethyl-phenyl) or 3-(4-chlorophenyl)-7-chloro-10-hydroxy- or -10-deoxy-3,4-dihydroacridine- 1,9(2H,10H)-dione 1-imines and 1-hydrazones, more than 45 showed an activity against asexual stages of Plasmodium berghei in the mouse which was comparable with or superior to that of floxacrine. More than 25 derivatives of the 3-(4-chlorophenyl)-floxacrine series and 3-(4-chlorophenyl)-10-deoxy-floxacrine series are more effective than floxacrine against Eimeria tenella infection in chickens. 1-Amino compounds of the various series proved of be generally inactive, as did fragments of the structure of and compounds related to floxacrine. Structure-activity relations are suggested on the basis of examples.

Acridines↗
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.

Age Factors↗
PubMed1986

Chemotherapeutically active anthraquinones. II. Aminomethylanthraquinones.

Basically substituted 2,6- and 2,7-bis-amino-methylanthraquinones have a pronounced in vitro and in vivo effect against Entamoeba hystolytica (extraintestinal amoebiasis in golden hamsters) and marked interferon-inducing properties. In 2,6- and 2,7-bis-aminomethyl-anthraquinones only the introduction of hydroxyl groups in 1,5 or 1,8 position led to an additional high systemic activity against Trichomonas foetus in NMRI mice, but it also resulted in the loss of the interferon-inducing effect. Both substance classes included several compounds whose effects against E. histolytica or T. foetus were either comparable or superior to those of standard compounds ornidazole and tinidazole.

Amebiasis↗
PubMed1985

Morphology of axons in the human lateral geniculate nucleus: a Golgi study in prenatal and postnatal material.

A study was made of rapid Golgi preparations from the lateral geniculate nucleus in humans aged from 28 weeks gestation to 70 years in order to identify axon terminals of afferent fibre systems. We describe three main axonal types using, as far as possible, nomenclature already adopted for other species. Type I axons were found only rarely. They are relatively straight with short, stalked side-branches and may represent cortico-geniculate fibres. Type II axons have complex, ball-like arborizations with large, irregular varicosities. They are common at all ages from gestation to maturity and are probably retinal in origin. Type IV axons (Type III was not used as no unequivocally intrinsic axons, for which the term has been used in the past, were identified) are branched, meandering and characterized by many, regular varicosities. Their origin is unclear, but may be related to non-specific brainstem sources. The basic morphology of Type II axons varies little between late gestation and adulthood, but Types I and IV seem to evolve during the perinatal period, perhaps from primitive forms that have similar morphological features. We conclude that the morphology of afferent axons to the human lateral geniculate nucleus is basically similar to that of lower mammalian species.

Adolescent↗
PubMed1985

Golgi and Nissl studies of the visual cortex of the bottlenose dolphin.

Nissl, Golgi and fibre preparations were made of the cerebral cortex of the lateral gyrus of the bottlenose dolphin (Tursiops truncatus) in the region where visual evoked potentials have been reported (Sokolov et al., '72; Ladygina et al., '78). In the adult the visual cortex is relatively thin (average about 1,300 micron) for so large a brain (fixed brain weight for a typical adult in our series was 1,330 g). Layers I, III, and VI are wide and represent three-quarters of the total cortical thickness. Layer I contains few cell bodies, while III and VI have a variety of pyramidal and nonpyramidal neurons. Layers II and V are narrow and contain striking palisades of darkly staining pyramidal cells that are particularly large in layer V. No clearly demarcated layer IV is present in the adult dolphin visual cortex. Many of the neurons identified with the Golgi technique are typical of pyramids in other mammals, with a single apical dendrite and a bouquet of basal dendrites, mostly highly spiny. Others are unusual in having bifurcated or oblique apical dendrites. Typical large and small spiny and nonspiny stellates are also found, mainly in layers III and VI. In addition various forms of spindle-shaped, bipolar and multipolar neurons are found in most layers. An 18-day-old brain shows signs of immaturity in its visual cortex. It is thinner (970 micron) and on average its neurons are smaller, paler, and more densely packed. Especially the pyramids of layer V are much smaller than in the adult. Also, a distinct "granular" band occurs between layers III and V and seems to be a rudimentary layer IV. At 3 years of age most of the adult features have developed, but layer IV is still detectable. No striking differences were observed in cell and fibre architecture between the cortex of the lateral gyrus and that of the so-called "calcarine" area that has also been considered as "visual." We concluded that, although different in many respects from other mammalian visual cortices, that of the dolphin is apparently well developed and differentiated.

Aging↗