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L Werner

Publications and source records attributed to L Werner.

At least 109 records · Page 6Linked to original sources
PubMed1984

[Sparsely-spined neurons in the rat visual cortex].

Sparsely spined neurons were described in the visual cortex of the rat. A large cell type was found in all laminae, but mainly in L III-L V. The soma is large and the dendrites are vertically oriented. In most cases, the axon originates from the upper main dendrite or the upper soma pole. The axonal arborization is vertical. In the terminal axonal segments the number of boutons is high. A small neuron type could be demonstrated in L IV. The soma is small, and the dendritic field is nearly multipolarly or horizontally oriented. The axon derives from the basal pole or laterally at the soma.

Animals↗
PubMed1984

Neuron types in the rat dorsal lateral geniculate nucleus identified in Nissl and deimpregnated Golgi preparations.

To identify geniculo-cortical relay neurons (GCR-neurons) and interneurons (I-neurons) in Nissl stained sections of the albino rat's (Wistar strain) dorsal lateral geniculate nucleus (dLGN) we combined a Golgi deimpregnation technique (Fairén et al. 1977) with the Nissl staining. The two types of neurons show numerous characteristic features in Golgi preparations (Brauer and Schober 1973, Grossman et al. 1973, Brauer et al. 1974, Winkelmann et al. 1976, 1979). After application of the combined method it is obvious that neuronal somata exhibit also features which make it possible to identify these types of neurons in Nissl stained series. GCR-neurons are characterized by a very broad cytoplasmic portion, whereas a particularly thin cytoplasm rim is typical of I-neurons. Our findings confirm former results obtained by analysis of Nissl material (Werner and Kruger 1973, Werner et al. 1975, Werner and Winkelmann 1976, Werner et al. 1984). In these investigations, special attention was paid to cytoplasmic and nuclear characteristics in order to elucidate the ratio of GCR-/I-neurons (13:1) and the internal dLGN topography. It is still discussed if the described cytological features can be taken as basis for the classification of GCR- and I-neurons in other species.

Animals↗
PubMed1984

[Morphometric analysis of the dorsal lateral geniculate body of the laboratory mouse and microphthalmic variants].

The dorsal lateral geniculate nucleus (dLGN) of the mouse (strain 944 with microphthalmus syndrome, P. Hertwig 1942) has been morphometrically investigated. The eyes of the gray littermates develop normally (control animals) while the white littermates show the microphthalmus syndrome (microphthalmic animals). Four male twentyone day old animals were examined. Following perfusion with formaldehyde (diluted 1:4 with H2O) Nissl stained frontal sections were used for classification of neurons. we differentiate between projection neurons (PN) (geniculo-cortical relay neurons) and interneurons (IN). We succeeded in identifying these two cell types using deimpregnated Golgi preparations (Fairén et al. 1977), which were counterstained with methylene blue (0.1%). The neuronal packing density and the ratio PN:IN were conventionally determined using 20 micron thick sections from both control and microphthalmic animals. In both cases this ratio was 12:1 (= 8% IN). Measuring fields distributed in a meander-like manner were selected for estimating the neuronal density. Measuring fields giving equal values were connected. The results show that we can distinguish between 3 regions of dLGN: lateral, medial and caudal. They differ with regard to neuronal packing density, size and structure of the PN. Using 3 micron thick Nissl stained sections from both control and microphthalmic animals the size and structure of PN were automatically determined using the picture processing device "MORPHOQUANT" VEB Carl Zeiss JENA). The distribution pattern of IN is apparently uniform. The microphthalmus syndrome produces a diminished number of pathologically changed retinal fibers. The morphometrically registered findings show that within the dLGN, of the microphthalmus mouse the neuronal packing density increased (diminution of neuropil), the size of PN decreased and their structural density increased (transneuronal dystrophy). Compared with the other parts, the medial part of the dLGN is minimally altered.

Animals↗
PubMed1984

The ventral lateral geniculate nucleus of the albino rat morphological and histochemical observations.

The ventral lateral geniculate nucleus (vLGN) of albino rats (Wistar strain) has been described histologically and histochemically. Special attention was paid to the identification of cell classes in Nissl and Golgi preparations, the afferent and efferent connections of vLGN cells and the demonstration of enzymes of energy and transmitter metabolism. Topographical aspects were taken into consideration, too. The main results can be summarized as follows: In the rat vLGN, three subnuclei can be distinguished: the lateral and medial subnucleus and the intergeniculate leaflet. In the rostral vLGN, the lateral and medial subnucleus is separated by a vertical fibre bundle which contains retinal axons. Our own experiments and findings of other groups revealed that the rat vLGN is connected with numerous brain structures. There is no efferent projection to cortical regions. Afferent fibres reach the vLGN from retina, visual cortex, superior colliculus, pretectal region, zona incerta, contralateral vLGN, dorsal raphe nucleus, locus coeruleus, mesencephalic reticular formation, vestibular and dorsal tegmental nuclei. An efferent projection has been found to superior colliculus, pretectal region, dorsal lateral geniculate nucleus, contralateral vLGN, zona incerta, pontine nuclei, suprachiasmatic nucleus, lateral terminal nucleus of the accessory optic system and intralaminar nucleus of thalamus. Comparative findings suggest that the lateral subnucleus is involved in "specific projections", whereas the medial subnucleus projects to "unspecific zones". For detailed information see text. Five classes of neurons can be distinguished in Golgi and Nissl preparations. Class 1 cells are medium-sized to large with smooth thick proximal but branched spiny distal dendrites. They are confined to the lateral subnucleus and the intergeniculate leaflet. In the lateral subnucleus, class 1 cells could be identified as geniculo-tectal relay neurons (Brauer and Schober, 1982). All other classes of neurons are spineless or sparsely spined. Class 2 cells (giant neurons) of unknown function could be found in the lateral and medial subnucleus. Class 3 cells (medium-sized multipolar neurons) can mainly be found in the medial subnucleus. They are good candidates for neurons projecting to the contralateral vLGN. Class 4 cells (bipolar neurons) occupy the ventromedial part of the medial subnucleus and are very similar to cells localized in the adjacent zona incerta. Cells belonging to this type could found to be labelled by the HRP reaction product after injection of this enzyme in the pontine region.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholinesterase↗
PubMed1983

Effect of combined haloperidol-lithium treatment on vitro RBC lithium uptake in patients with affective disorders.

Combined treatment with haloperidol and lithium is a frequently employed strategy for the treatment of acute psychoses. Although this combination regime is safe in most clinical situations, under certain circumstances it has resulted in neurotoxicity, with organic brain syndrome, and ultimately, in some patients, irreversible brain damage and death. Plasma lithium levels in these neurotoxic patients are generally within the clinically acceptable range of 0.7 - 1.5 mEq/l, but RBC-lithium levels, when reported are abnormally elevated. To account for these observations we hypothesized that in vivo haloperidol will alter the transport of lithium across the RBC membrane and thus cause an increase in RBC lithium levels. We report preliminary results from a study that tested this hypothesis by measuring RBC lithium transport in vitro, in patients treated with a) haloperidol only, b) haloperidol, followed by haloperidol and lithium, c) combined haloperidol and lithium. In eight manic depressive patients in vivo haloperidol alone, or in combination with lithium resulted in a statistically significant (p less than 0.0001) reduction of the in vitro RBC Li+ uptake values. These results are interpreted as supportive of our hypothesis, that in vivo haloperidol alters the transport of lithium across the RBC membrane, and this effect can be detected by the use of a sensitive in vitro test. Work is currently in progress to evaluate, whether the RBC Li+ transport alteration is due to a direct effect of the drug on the cell membrane or secondary to some circulating factor, and to extend these findings to a larger sample of patients.

Bipolar Disorder↗
PubMed1983

[Degenerative changes in the occipital neocortex in chronically amphetamine treated rats].

Neurons of the Wistar-rats' occipital cortex were morphologically investigated after chronical application of amphetamine. The nerve cells impregnated according to the Golgi-Kopsch technique showed in part changes on both the dendrites and in the axonal region. Besides a partial reduction of spines and of peripheral dendritic arborizations round varicosities of different density could be observed on the dendrites and on the axon, either, which were discussed to be due to a neurotoxic effect of amphetamine.

Amphetamine↗
PubMed1982

A comparative light microscopic investigation on geniculo-cortical relay neurons in rat, tree shrew and cat.

The morphology of geniculo-cortical relay neurons (GCR-neurons) of tree shrew, rat and cat differs intraspecifically and interspecifically from each other. Intraspecific differences in the cat have been explained functionally by the W-, X-, and Y-characteristics of cells (Wilson et al. 1976). Analogous morpho-functional correlations may also explain the morphological differences in tree shrew and rat. The interspecific differences in the morphology of GCR-neurons seem to be closely correlated to the levels of visual specialization in the three species in which the rat represents a basal developmental stage.

Animals↗
PubMed1982

Topographical distribution of neuronal types in the albino rat's area 17. A qualitative and quantitative Nissl study.

1. Using Nissl preparations of adult male albino rats the topographical distributions of 10 neuronal types of the area 17 were ascertained in medio-lateral and dorso-ventral direction. 2. Two groups of neuronal types and one intermediate type are distinguished: (i) neurons rich in cytoplasm: pyramidal cells in L II-VI, stellate cells in L IV, one type each in L I and L VII, and a particularly large neuronal type in L II-VI; (ii) neurons poor in cytoplasm: one type in L I, three types in L II-VII and (iii) the intermediate type in L II-VI. 3. In the area 17, 93% of neurons are rich in cytoplasm (except the particularly large neuronal type B, 3.5%) (category-I-neurons = projection neurons), 2.9% of neurons are poor in cytoplasm (category-II-neurons = interneurons), and 0.6% are of the intermediate type. The latter may correspond with the Martinotti cell. At present we can only speculate, which cell type in Golgi preparations corresponds with the type B. 4. Taking into account the shrinkage of histologically treated tissue the number of neurons within a fresh volume of area 17 can be estimated. There are about 40,000 neurons within a volume of 1,000 microns x 1,000 microns basis. 5. Each layer is characterized by a specific amount of certain neuronal types, which are intermingled. 6. The distribution pattern of neuronal types change considerably in dorso-ventral direction. Medio-laterally there are only random deviations. 7. There are much more neurons poor in cytoplasm in superficial layers than in deeper layers. 8. In L I and L Va the highest and in L VII the smallest percentage of neurons poor in cytoplasm could be found. 9. L IV is characterized by its high number of stellate cells, the relatively high portion of the particularly large neuronal type B and small portions of pyramidal cells and neurons poor in cytoplasm. 10. As far as possible the functional aspects of the presented findings are discussed.

Animals↗
PubMed1982

Perineuronal nets of glia.

Perineuronal nets could be visualized with some Golgi methods in the rat's brain. Nets were seen in telencephalic, diencephalic and mesencephalic structures covering somata and proximal dendrites of different neuronal types. Some nets could be found originating from microglia cells. In most cases their origin is not recognizable. These perineuronal nets seem to be identical with "Golgi nets" of late anatomists, which played an important role in the discussion between recticularists and neuronists. Some aspects of their possible functional significance are discussed.

Animals↗
PubMed1981

[Age related classification of neurons in the rat visual cortex: a Nissl study (author's transl)].

Using Nissl preparations, 6, 8, 12, 16, 20, 30, 90, and 420 days old albino rats were investigated with regard to classification of several neuron types within layer IV and adjacent zones of layers III and V. Increasing maturation of the nervous tissue provides a greater classifiable variety of neuron types. About between the second and third postnatal week the degree of classification reach partially almost the same level as in the adult animals. Particular attention is paid to a large, frequently bipolar neuron type rich in cytoplasm.

Aging↗
PubMed1981

The dorsal lateral geniculate nucleus of Tupaia glis: a Golgi, Nissl and acetylcholinesterase study.

Morphology of neurons and afferent axons in the dorsal lateral geniculate nucleus (dLGN) of the tree shrew (Tupaia glis) was studied using Golgi-Kopsch impregnated and Nissl stained material. Staining of acetylcholinesterase (AChE) could inform about the distribution of this enzyme in the tree shrew's dLGN. The results can be summarized as follows: 1. Two classes of neurons can be identified: class-I-neurons and class-II-neurons. Class-I-neurons correspond to geniculo-cortical relay neurons (GCR-neurons) and class-II-neurons correspond to local interneurons (I-neurons). 2. Class-I-neurons differ in their morphology depending on their laminar position. Tufted neurons with clusters of grape-like appendages in their branching zones resembling X-cells in the cat's dLGN are localized in the external laminae 5 and 4. In the superficial lamina 6 the dendrite domains of GCR-neurons are flattened and elongated. Dendrites seem not to penetrate laminar borders. The cells in layer 3 have the smallest soma and radiate dendrites. There is some evidence that GCR-neurons in this lamina represent W-cells (Carey et al., 1979). GCR-neurons in laminae 2 and 1 (innermost laminae) have the biggest somata. Their dendritic branching patterns make it difficult to classify the cells into tufted or radiate. Branching zones are rather smooth. These cells seem to be good candidates for Y-cells. 3. I-neurons could be identified in all laminae. Their dendrites preferentially take a dorso-ventral course. Only axon initial segments of these neurons were visible in Golgi preparations. 4. GCR-neurons and I-neurons could also be identified in Nissl preparations. The ratio GCR-neurons: I-neurons is about 10:1, i.e. 10% of all neurons are I-neurons. 5. In Golgi preparations some types of axons were impregnated. Type-1-axons resemble cortical afferents of other mammalian species. Type-2-axons (2a, 2b, 2c) do not leave single laminae in our material. Considering branching characteristics of their terminal zones, this finding could be a reference for their retinal origin. 6. Laminae 5, 4, 2, and 1 have a remarkable higher content of AChe than the laminae 6 and 3. The low level of ACHE in lamina 3 of the tree shrew's dLGN corresponds to the less activity of ACHE in the laminae 4 and 5 of Galago senegalensis (Fitzpatrick and Diamond, 1979), which like lamina 3 in Tupaia's dLGN project to layer I of the visual cortex (Carey et al., 1979).

Acetylcholinesterase↗
PubMed1981

Age-related classification of pyramidal and stellate cells in the rat visual cortex: a Nissl study with the 'Morphoquant'.

(1) Using Nissl preparations and the automatic picture processing system 'MORPHOQUANT', VEB Carl Zeiss JENA, age-related classification of pyramidal and stellate cells of the layer IV in the rat's visual cortex was performed. (2) 12, 16, 20, 30, 90, and 420 days old animals were investigated. (3) Due to the high cell density and immature stage the neurons of an 8-day-old animal could not be measured. (4) A review is given about the automatic picture processing system 'MORPHOQUANT' and the applied computer program. (5) The analysis of one cell soma with the 'MORPHOQUANT' amounts to about 30 seconds. (6) The computer accepted 30 to 50% of the offered objects. The remaining ones could not be discriminated from the neighbourhood. (7) 14 standard features are registered and 7 statistically evaluated preferential taking into consideration area, form and texture of the objects. (8) 4 features are statistically relevant: soma area in picture points (KOFL) and whole extinction (EXTS) correspond to soma size; compactness (KOMP) and concentration of high grey values in the central part of the object (ZNTR) correspond to structural features of the soma, i.e. the structural density and the distribution patterns of strong coloured RNA and DNA particles. Form factors are not statistically relevant. (9) With increasing age the morphological features are clearer and the performance of the classificator is higher. (10) Soma size and structure of pyramidal and stellate cells develop similarly to an overshooting growth curve. The values reach the maximum approximately on postnatal day 16. (11) Age-related methodological and neurobiological problems are discussed.

Aging↗
PubMed1979

[Variability of the relay neurons in the corpus geniculatum laterale, pars dorsalis in the albino rat].

38 Golgi-impregnated relay cells from the Wistar rat's dLGN were investigated considering their possible differentiation into 2 types using camera lucida drawings with a magnification of 800. The following criteria were taken into account: 1. size of neurons (perikarya, size of dendritic domains) 2. structure of dendrites (number of dendrites, branching points, distribution of dendritic density in relation to the perikaryon, surface structures of dendrites). It was tried to correlate the investigated parameters quantitatively and qualitatively. The results showed that inspite of a missing clear subdivision into 2 types there exists a trend towards developing a second type of relay cells.

Animals↗
PubMed1979

[Classification of nerve cell forms in lamina IV of the visual cortex of albino rats using Nissel preparation with the help of automatic picture processing].

1) Using the automatical picture processing device "MORPHOQUANT", VEB Carl Zeiss Jena, layer IV of the adult albino rat's area 17 was investigated in Nissl-preparations to classify pyramidal and stellate cells on the basis of quantitative features. 2) A review is given about the applied computer programme. 3) 30 seconds are necessary for adjustment, measurement and statistical calculation. 4) Five features per neuron soma were registered and statistical calculated: neuron area in picture points (KOFL), mean value of extinction (EXTM), total extinction (EXTS), shape (i.e. dia ratio, DMVH), and the distribution of strong coloured particles (i.e. centricity, ZNTR). 5) High statistical significance could be achieved only with regard to the neuron area and the distribution of strong coloured particles. 6) The causes for different results obtained in previous and present measurements and the importance of differentiation between several types of neurones are discussed as well.

Animals↗
PubMed1979

[Cytomorphometry of area 17 of the albino rat using the automatic picture processing].

Using the automatical picture processing, the layers II to IV of the adult albino-rat's area 17 were investigated in Nisselpreparations. Within 15 hours 14 features from approximately 10 000 neurons could be registered. Five features (neuron density = neuron number per 10 areas of measurement, mean value of neuron area in picture points, mean value of mean extinctions of neurons, whole extinctions of neurons, mean value of relative granula area of neurons) were statistically calculated and considered under several aspects: 1st Concerning the specifity of the layers very exact results could be obtained. 2nd In a detailed investigation of the lamina V pyramidal cells estimating somata areas no statistically significant classification could be achieved. 3rd There are slight structural changes of area 17 in rostrocaudal direction, but without statistical significance. Further investigations are necessary. 4th It is possible to differentiate between pyramidal cells and stellate cells of lamina IV. The numerical proportion between these two types of cells, however, deviates from individual estimations. Until now, this problem could not be satisfactorily be solved.

Animals↗
PubMed1979

[Identification of nerve cells in the visual cortex of the rat using Nissl and Golgi-Kopsch methods].

The neurons of the visual cortex of the albino rat were studied using both the Nissl- and Golgi-Kopsch methods. In Nissl preparations we can distinguish between a group of neurons rich in cytoplasm, a group of neurons poor in cytoplasm and an intermediate group. In the Golgi preparations the neurons can be subdivided according to the shape of their cell bodies, dendrites and axons. Spiny cells with long axonal main trunks are pyramidal cells, multiangular cells and stellate cells of layer IV. Cells with spineless dendrites and short axonal arborization are basket cells, neuroglioform cells and small double bouquet cells. Due to its spines and the short axonal arborization, the coarse fusiform cell (Martinotti cell) is an intermediate type. We assume cells having long axons and dendritic spines are category I neurons and cells having short axons and no or a few spines are category II neurons (according to SZENTAGOTHAI 1973). On the basis of homological criterions and taxonomically relevant features references for identifying the cell group rich in cytoplasm and category I neurons, on the one hand, and the cell group poor in cytoplasm and category II neurons, on the other hand, were found. The group of cells rich in cytoplasm is related to pyramidal cells, multiangular cells and stellate cells of lamina IV. The group of cells poor in cytoplasm is discussed as corresponding to cells of lamina I, round or oval forms as basket cells and neuroglioform cells, fusiform cells as double bouquet cells. The intermediate cell form in the Nissl preparations is according to the Martinotti cell in Golgi material. These findings allow quantitative studies about particular cell populations and can, completed with electron microscopical date, instruct computer models to simulate the complicate neuronal network of the visual cortex.

Animals↗