PubMed Health⌕ Search

Biomedical subjects

N A Uranova

Publications and source records attributed to N A Uranova.

At least 19 recordsLinked to original sources
PubMed2005

Organotypic cultures of free-floating slices of human embryo medulla oblongata.

The aim of the present work was to produce organotypic cultures of human embryo brain tissues, as needed for investigation of the effects of serum factors on mental diseases and their pharmacological treatment. Cultures were made using slices of medulla oblongata from human embryos aged 9-10 weeks, obtained from medical abortions. Free-floating slices were cultured using a modified roller method for four weeks. Light and electron microscopy, along with immunocytochemistry, demonstrated that cultured slices showed differentiation and growth of neurons, astro- and microgliocytes, with formation of the synaptic contacts and glioneuronal interactions typical of organotypic cultures. However, along with differentiated neurons and glial cells, there was some persistence of undifferentiated cellular elements with signs of stem cells and neuron and gliocyte precursor cells. These experiments showed that organotypic roller cultivation of free-floating slices of human embryo brain tissue can be used to study the processes of neuron and gliocyte development, the mechanisms of neurotoxicity and neuroprotection using a variety of morphological (including stereological) and biochemical study methods.

Adult↗
PubMed2004

[Lowered oligodendroglial cell density in the prefrontal cortex in schizophrenia].

Using optical dissector methodology, a morphometric study of numerical density of oligodendroglial cells in layer VI and in adjacent white matter of Broadmann area 10 has been conducted in 23 postmortem brains of schizophrenics and 20 matched controls. Comparing to controls, a significant reduction of numerical density of oligodendroglial cells was found in layer VI (by 31%) and adjacent white matter (by 12%) of schizophrenic patients. The data obtained, as well as ultrastructural signs of oligodendroglial cells apoptosis and necrosis found earlier by the authors, may indicate a loss of these cells in the prefrontal cortex in schizophrenia, which may, in its turn, result in neuronal and high cortical dysfunctions.

Adolescent↗
PubMed2003

[Organotypic cultures of free-floating sections of human embryonic medulla oblongata].

The aim of the present study was the development of organotypic culture of embryonic nerve tissue of human brain, which is necessary for the study of the effect of blood serum factors in mental diseases and their medicinal treatment. For the cultivation the sections of medulla oblongata were taken from human 9-10 week embryos obtained at legal medical abortion. Free-floating sections were cultured using a modified roller method for 4 weeks. By using the methods of light and electron microscopy, as well as of immunocytochemistry, it was demonstrated that within the cultured sections the differentiation and growth of neurons, astrocytes and microgliocytes took place accompanied by the formation of synaptic contacts and the establishment of glial-neuronal relationships, characteristic to the organotypical cultures. However, along with the differentiated neurons and glial cells, undifferentiated cellular elements were partially retained, that had the signs of neuronal and glial stem cells and progenitor cells. The studies performed have demonstrated that the method of organotypic roller culture of free-floating sections of human embryonic brain tissue could be applied for the study of the processes of neuronal and gliocyte development, mechanisms of neurotoxicity and neuroprotection using various morphological (including stereological) and biochemical research methods.

Astrocytes↗
PubMed2001

[Morphometric study of ultrastructural changes in oligodendroglial cells in the postmortem brain in endogenous psychoses].

A qualitative and quantitative electron microscopic study of oligodendroglial cells was performed in autoptic (4-6.5 hours after death) prefrontal area 10 in 16 cases of schizophrenia, 6 cases of bipolar affective disorder and 16 normal controls, as well as in the caudate nucleus in same schizophrenic and control cases. The signs of reactive, regressive, and progressive changes of oligodendroglia were described in endogenous psychoses. ANOVA demonstrated a significant decrease in the area of the nucleus, in the volume density of euchromatin, in the volume density and count of mitochondria in oligodendroglial cells in the caudate nucleus and prefrontal area. In affective psychosis, there was a significant reduction in the area of the nucleus and in the volume density of euchromatin and slight changes in cellular organelles. No correlation between the changes and the postmortem interval, age, and neuroleptic therapy, as well as the most pronounced changes in oligodendroglial cells in subgroups of continuous schizophrenia and those with predominantly negative symptoms suggest the involvement of abnormal oligodendroglial cells in the pathogenesis of endogenous psychoses.

Aged↗
PubMed1997

[Synaptic contacts in schizophrenia: study with immunocytochemical identification of dopaminergic neurons].

Immunocytochemical identification of dopaminergic neurons was made by means of immunoperoxidase method using antibodies to tyrosine hydroxylase. The ultrastructure of synaptic contacts located on dopaminergic (tyrosine hydroxylase immunopositive--TP) neurons was investigated in substantia nigra (SN) of postmortem brains in 4 schizophrenic patients compared to 3 mentally healthy control cases. Various alterations of ultrastructure have been found in presynaptic terminals which contracted with TP neurons in SN of schizophrenic patients as compared to the control group. These alterations included: presynaptic axon terminals decreased in sizes with dense matrix and density packed vesicles; swollen terminals with clustering of synaptic vesicles and displaced active zone of synapse; hyperplasia of mitochondria in the part of presynaptic boutons; appearance of abnormal membranous lamellar structures inside or outside presynaptic boutons. The altered presynaptic terminals were preferentially located on distal (small and middle diameter) TP dendrites in pars compacta of SN, where practically all dendrites revealed belonged to dopaminergic neurons and formed asymmetric contacts with short active zones in most cases. The changes of ultrastructure of synaptic contacts could be rarely observed in SN pars reticulata of schizophrenic patients both on TP and tyrosine hydroxylase immunonegative dendrites presented here.

Adult↗
PubMed1996

[Brain synaptic plasticity in schizophrenia].

A qualitative and quantitative electron microscopic study was performed. in some postmortem brain structures of the dopaminergic system: the substantia nigra, ventral tegmentum area, prefrontal cortex (area 10), anterior cingulate cortex (area 24), the head of the caudate nucleus in schizophrenia and age-matched controls without mental disorders. The study revealed the heterogeneity of ultrastructural changes in synaptic ultrastructure and organization in schizophrenia as compared to controls. There was an anomalous sprouting of axons and a trend to increase the numerical density of axospinous synapses and to decrease axodendritic synapses in the schizophrenic brains due to disontogenesis or anomalous synaptic plasticity. No correlations with neuroleptic treatment were found. Synaptic plasticity might be involved in the pathophysiology and clinical symptoms of schizophrenic patients.

Adult↗
PubMed1995

[Synaptic plasticity and the glio-synaptic relationships of the rat hippocampus in age-related memory dysfunction].

Qualitative and quantitative studies of structural changes of synaptic contacts and processes were performed in aged memory-non-impaired an aged memory-impaired rats compared to young rats in the stratum lucidum of the hippocampus. Aged memory-impaired rats (compared with young adults) showed alteration in the ultrastructure of mossy fiber expansions and the loss of axospinous synapses formed by them. These changes were more pronounced than in memory-non-impaired rats. There were no significant differences between aged memory impaired and aged memory non-impaired rats except for a significant decrease in volume density of postsynaptic density in axodendritic synapses formed by mossy fiber expansions in memory impaired animals.

Aging↗
PubMed1995

[Mossy fibers of the hippocampus in Alzheimer's disease].

An ultrastructural study of changes in synaptic contacts and astrocytic processes of postmortem hippocampus was performed in 5 cases of Alzheimer's disease. Mossy fibres in the stratum lucidum were examined. Pronounced alterations included clustering of synaptic vesicles, membranous damage and multilamellar profiles in synaptic terminals. There were many hypertrophic astrocytic processes around synapses. The findings suggest that the ultrastructural alterations in mossy fibers expansion, and the disturbance of glio-synaptic relationships might contribute to memory impairment in Alzheimer's disease.

Aged↗
PubMed1991

Morphometric study of synaptic patterns in the rat caudate nucleus and hippocampus under haloperidol treatment.

A morphometric study of the synapses on dendritic shafts and spines was performed in the rat caudate nucleus and the CAI area of the hippocampus under chronic haloperidol treatment. In the nucleus caudatus, the synaptic density on dendritic shafts increased by 83% and those on spines by 53%. Most of the parameters measured in axospinous synapses were significantly increased: the area of presynaptic axon terminals (20%), the number of mitochondria per axon terminal (51%), the length of active zone (11%), the area of postsynaptic density (23%), and the perimeter of postsynaptic density (12.5%). The area of postsynaptic spines showed no changes. In the synapses on dendritic shafts, the area of presynaptic terminals decreased (31%), the area of mitochondria per terminal decreased (40%), the length of active zone increased (14%), and other parameters were unchanged. There were no significant differences in the same parameters measured in the hippocampus. The data are discussed as morphological correlates of behavioral supersensitivity and dopamine D2 receptor up-regulation.

Animals↗
PubMed1991

[Electron-microscopic analysis of cytoarchitectonic disorders in the cerebral cortex in schizophrenia].

Microscopy and electron microscopy were used to examine foci of neuronal loss in the 2nd-3rd layers of the prefrontal cortex of the autopsy brain from 8 schizophrenic patients and 8 controls without any mental pathology. No signs of gliosis were identified. Foci of neuronal loss showed multiple accumulations of the thin bundles of unmyelinated fibers not discovered in the control, dystrophic-changed astrocytes, swollen dendrites free of microtubules. The changes in synapses on dendritic spines and shafts in these areas of neuropile were discovered to be functional and dystrophic in nature.

Adult↗
PubMed1990

[Morphometric analysis of synaptic contacts in the anterior limbic cortex in endogenous psychoses].

Electron microscopic morphometric study of synaptic contacts on dendritic spines and shafts was performed in layer II of the anterior cingulate cortex (area 24) of autopsy brain of paranoid schizophrenics (n-5), manic-depressive patients (MDP) (n-2) and controls (n-7). The areal synaptic density on dendritic spines increased significantly (p less than 0.001) in both groups of endogenous psychosis. The synaptic density on dendritic shafts decreased by 40% in schizophrenia and did not differ from controls in MDP. In schizophrenia, the percentage relations between different forms of synapses on dendritic spines (convex, concave and flat; symmetric and asymmetric; perforated and ++non-perforated++) differed from MDP and controls.

Aged↗
PubMed1990

Synaptic plasticity in rat medial prefrontal cortex under chronic haloperidol treatment produced behavioral sensitization.

Morphometric analysis of the population of synapses in medial prefrontal cortex (layer VI) of rat treated daily with haloperidol in a dose of 1.0 mg/kg during 3 weeks was performed on the electronmicroscopic level. The density of synapses on dendritic shafts increased on 29% and on the head of spine it increased on 20%. Nearly all the parameters measured in axo-spinous synapses were significantly decreased (area of presynaptic terminal, summarized area of mitochondriae per terminal, number of synaptic vesicles near the active zone, area of postsynaptic spine). There were no differences between the parameters of axo-dendritic synapses in control and haloperidol-treated rats. The data suggest that haloperidol might have induced the formation of the new synapses and may have changed the efficacy of the synaptic transmission in axo-spinous synapses on the head of spine.

Animals↗
PubMed1989

The effects of amphetamine on synaptic plasticity in rat's medial prefrontal cortex.

Morphometric analysis of medial prefrontal cortex (layer VI) of rats treated daily with amphetamine in a dose of 2.5 mg/kg during 3 weeks was performed on the electron microscopic level. The efficacy of the amphetamine dosage was tested on behavioral observation. Synapses on dendritic shafts and spines were studied. The density of axo-dendritic synapses increase on 74%, while the density of synapses on spine's neck decreased on 53%. Most synaptic parameters measured in axo-dendritic (1) and axo-spinous (2) synapses increased significantly under the influence of 2.5 mg/kg dose of AMPH: area of presynaptic terminal increased on 35% (1) and 21% (2), length of postsynaptic density increased on 13% (1) and 12% (2), area of spine increase on 25%. But the density of synaptic vesicles near the active zone decrease (1-on 16.5%, 2-on 20%).

Amphetamines↗