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M Vankova

Publications and source records attributed to M Vankova.

13 recordsLinked to original sources
PubMed1996

Opposite changes in the expression of enkephalin in the amygdala and hypothalamus after lesions of the bed nucleus of the stria terminalis in the rat.

The expression of enkephalin in neurons of the rat forebrain was studied by in situ hybridization and immunohistochemistry after unilateral injections of ibotenic acid into the bed nucleus of the stria terminalis. Initially, we observed that the destruction of nerve cell bodies in this nucleus resulted in a prominent bilateral increase in the number of neuronal perikarya immunoreactive for [Met]enkephalin in the lateral/basolateral amygdaloid complex-especially in the anterior division of the latter nucleus-as compared with NaCl-injected rats. In a separate set of experiments, this effect was associated with a significant (two times) enhancement of the number of nerve cell bodies containing preproenkephalin A messenger RNAs in the same amygdaloid nucleus ipsilateral to the injection, as compared with controls. In the hypothalamus of both experimental and control rats, the nerve cell bodies immunoreactive for [Met]enkephalin were few since the animals were not pretreated with colchicine, and the effects of the lesion were difficult to appreciate. However, using in situ hybridization, numerous nerve cell bodies containing preproenkephalin A messenger RNAs were detected bilaterally in the perifornical area, the paraventricular (parvocellular division) and the ventromedial nuclei of the hypothalamus. In the latter nucleus, the lesion of the bed nucleus of the stria terminalis resulted in a strong decrease (about two times) in the number of labelled cell bodies as compared with the controls, whereas no significant changes were found bilaterally in the paraventricular nucleus. In agreement with some data of the literature, our results indicate that the bed nucleus of the stria terminalis plays an important role in the regulation of neuropeptide genes expression in certain regions of the limbic system. Such a role is often exerted by nerve fibres afferents to the nerve cell bodies considered. However, from numerous neuroanatomical data of the literature, it appears more probable that the induction or inhibition of the expression of enkephalin in presynaptic neurons is due to the disappearance of their postsynaptic target in the bed nucleus of the stria terminalis.

Amygdala↗
PubMed1995

Changes in the neuronal plasma membrane during synaptogenesis.

During synaptogenesis the plasma membrane of neurons undergoes considerable changes and large portions of it develop to synaptic membranes. This transformation is brought about by biochemical and morphological changes. The aim of the present investigation was to study by morphological methods the in vivo changes of some basic components of the neuronal membranes during the early postnatal period, when active synaptogenesis occurs. The cerebral cortex of Wistar rats was used for preparation of either growth cones (up to postnatal day 10) or synaptosomes (postnatal days 14-30). Our studies were focused on the changes occurring in integral membrane proteins and cholesterol domains, and in certain carbohydrate residues and anionic sites. In the first days after birth relatively few intramembranous particles are found in the plasma membranes of growth cones, few and small cholesterol domains, scarce lectin-binding and anionic sites. During the following days there is a clear tendency for increase of the number of all of the studied structures until the appearance of typical synaptic membranes. Throughout the studied developmental period the protein and the cholesterol molecules were found to occupy distinct membrane domains. The structure of the developing neuronal membrane, poor on proteins and cholesterol, and its maturation to the fully functional synaptic membrane is discussed.

Age Factors↗
PubMed1994

Demonstration of peptidergic afferents to the bed nucleus of the stria terminalis using local injections of colchicine. A combined immunohistochemical and retrograde tracing study.

In the present study, we demonstrate the existence of numerous peptidergic afferents to the bed nucleus of the stria terminalis (BNST) using the retrograde transport of gold-labeled wheat germ agglutinin-apo-peroxidase (G-WGA-HRP) combined with the indirect immunoperoxidase method after intraparenchymatous injections of colchicine. At first, we show that local injections of colchicine alone into the BNST are able to induce the retrograde accumulation of peptides until the nerve cell bodies of origin, probably because of the blockade of axonal transport in nerve terminal arborizations innervating this nucleus. The actual existence of putative peptidergic afferents to the BNST indicated by the local injections of colchicine was established using: a) the retrograde transport of G-WGA-HRP from the BNST combined with immunocytochemistry after administration of colchicine at the same place, b) the anterograde "transport" of the fluorescent tracer DiI from selected nuclei of the forebrain. We demonstrate that the neurons immunoreactive for enkephalins, neurotensin, or substance P that innervate the BNST are localized mainly in the central amygdaloid nucleus, the paraventricular thalamic nucleus, and the ventromedial hypothalamic nucleus ipsilateral to the injection, as well as bilaterally in the magnocellular paraventricular and perifornical regions of the hypothalamus. From these results it may be concluded that intracerebral injections of colchicine constitute a powerful tool to search for multiple peptidergic afferents to a given brain nucleus using only immunohistochemistry. The existence of these pathways, however, must be verified by other neuroanatomical methods because of the problem of nerve fibers of passage.

Animals↗
PubMed1991

Enkephalin-containing nerve cell bodies in the substantia nigra of the rat: demonstration by immunohistochemistry and in situ hybridization.

The use of a new and very sensitive immunohistochemical method, combined with intracerebral injections of colchicine, has allowed us to show that a number of nerve cell bodies immunoreactive for Met-enkephalin are present in several mesencephalic nuclei of the rat, including the different subdivisions of the substantia nigra (SN). The existence of numerous neuronal somata of this kind in the medial part of the SN pars compacta and in the lateral half of the pars reticulata is rather new. The latter has been ascertained by demonstrating a perikaryal immunoreactivity for synenkephalin in the same regions of the SN. In addition, by in situ hybridization, we have shown that neuronal cell bodies expressing the preproenkephalin A (PPA) gene are also present in the same regions of the SN. However, the fact that a strong radioautographic reaction was found only in rats which received an intranigral injection of 6-hydroxydopamine indicates that these neurons are probably not dopaminergic and that an induction of the PPA gene occurs in these animals.

Animals↗
PubMed1991

Gap junctional vesicles in the neointimal smooth muscle cells of balloon injured carotid artery.

After balloon injury of the carotid artery in the rat, gap junctional vesicles were frequently detected in neointimal smooth muscle cells. They represent spherical structures confined by pentalamellar membrane containing a fine filamentous and granular material inside. Since gap junctional vesicles are not typical for the medial smooth muscle cells their occurrence in the intimal cells may be related to their secretory function and/or proliferative capacity.

Animals↗
PubMed1990

Origin of some enkephalin-containing afferents to the ventro-medial region of the globus pallidus in the rat.

The retrograde transport of WGA-HRP adsorbed to colloidal gold was combined with the indirect immunoperoxidase technique to study the origin of enkephalin-containing afferents to the medial and ventral regions of the globus pallidus (GP). On the injected side, the nerve cell bodies labeled retrogradely or double labeled were numerous in the central nucleus of the amygdala (ACe), scattered in the bed nucleus stria terminalis (BNST) and few in the fundus striati. In the ACe, approximately 40% and 20% of the retrogradely labeled perikarya were found immunoreactive for Met-enkephalin and Leu-enkephalin, respectively, whereas they were only 30% and 15% in the BNST. It is concluded that the enkephalinergic afferents of the ventro-medial region of GP, which contains the basal nucleus of Meynert in the rat, are largely of limbic origin.

Amygdala↗
PubMed1989

[Changes in the distribution of negatively charged sites of the synaptosomal membrane in adult rats].

Changes in the distribution of Anionic sites on the synaptosomal membrane of old rats were investigated by means of cationized ferritin. Synaptosomal fraction was isolated from the cerebral cortex of two groups of rats: a control group-rats aged 2 months and second group-rats aged 14 months. Some diminishing of density was established on anionic sites as well grouping in larger or smaller aggregates of the same sites on the membrane of some synaptosomes of old rats.

Animals↗
PubMed1985

Internal organs of the conjoined twins.

Described are the alimentary system, the respiratory system, the urogenital system and the endocrine glands of conjoined female twins. There were found to be present 2 esophagi, 2 stomachs, 2 duodeni, 2 pancreas and one large liver. The intestine is unique from the region of the jejunum to it's end. There were found to be present 2 tracheae and 4 lungs. The urogenital system appeared to be normal. A single deviation was noted with respect to the endocrine glands, in particular, the right adrenal gland had an additional part which entered the thorax through a cleft in the diaphragm.

Adrenal Glands↗
PubMed1984

Peculiarities of the bones, muscles, and nervous system of the conjoined twins.

The peculiarities of the skeletal, muscular, and nervous systems of conjoined female twins (2 spines, one pelvis) is described judging from the examination of the 2 skulls, 2 vertebral columns, shoulder girdle of the intermediate connection between the trunks, deep muscles of the back, 2 separate central nervous systems, lack of changes in the muscles, of the anterior aspect of the thorax and anterolateral muscles of the abdomen; from what we have observed it is suggested that this is a case of uniovary twins whose separation began in the superior dorsal side but was incomplete in the ventral inferior parts. It is possible that this arose from accidents of fusion or fission of embryos.

Abnormalities, Multiple↗
PubMedDate not supplied

Afferent connections of the rat substantia nigra pars lateralis with special reference to peptide-containing neurons of the amygdalo-nigral pathway.

The afferent connections of the rat substantia nigra pars lateralis have been studied using the retrograde axonal transport of fluorescent latex microspheres. The most numerous groups of retrogradely labelled nerve cell bodies were observed bilaterally in the parabrachial complex and several hypothalamic nuclei, whereas the parietal neocortex, the fundus striati, the central nucleus of the amygdala and the bed nucleus of the stria terminalis were labelled on the injected side only. The neuronal projections from the central amygdaloid nucleus to the substantia nigra pars lateralis and lateral part of the rostral pars compacta have additionally been confirmed by anterograde tracing using wheat-germ agglutinin coupled to horseradish peroxidase. The presence of some peptides in this pathway was studied by combining the use of the same retrograde tracer with immunofluorescence after intra-amygdaloid injections of colchicine. With this method, we have demonstrated that Met-enkephalin, dynorphin and neurotensin are probably utilized as neurotransmitters or co-transmitters in the neurons of the amygdalo-nigral pathway.

Afferent Pathways↗