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N I Medvinskaia

Publications and source records attributed to N I Medvinskaia.

13 recordsLinked to original sources
PubMed2003

[Morpho-functional changes of neurons in temporal cortex in comparison with spatial memory in bulbectomized mice after treatment with minerals and ascorbates].

The effect of antioxidant mixture of mineralascorbates (MA) on the status of neurons of brain temporal cortex and behavior of mice after olfactory bulbectomy (BE) was studied, as it was previously shown by us that these animals were characterized by a deficit of spatial memory and development of neurodegenerative process in brain structures, which are affected by Alzheimer disease. Disorganization of cytoarchitectonics of temporal cortex with the deletion of its layers as a result of dystrophy of pyramidal neurons and foci of their complete disappearance were shown 1 month after BE. The increased number of neurons with the phenomena of karyopyknosis, karyolysis and vacuolysis was observed with a concomitant reduction in neuronal density. Addition of MA to the diet for three weeks prevented the development of deterioration of spatial memory in mice after BE and protected the neurons of brain temporal cortex from the degenerative changes. The results obtained suggest the possibility of realization of prophylaxis aimed at the prevention of the development of Alzheimer-type neurodestructive processes.

Animals↗
PubMed1999

[Effect of the preparation baliz-2 on the integrative brain activity and biogenic amine metabolism in rats under stress].

Effects of balis-2 on exploratory activity in the open field and elevated plus-maze, attention to sensory stimuli of different modalities, elaboration and retention of conditioned reflexes with food reinforcement, were studied in rats under stress. Prolonged treatment of rats with balis-2 seems to normalise integrative activity and metabolism of serotonine and dopamine in the animal brain.

Animals↗
PubMed1996

[The role of serotonin in the effects of cholecystokinin-8 on memory in rats].

The HCK8 was found to inhibit the field search behaviour in rats. Administration of the peptide impairs formation and reproduction of a habit within 1 hour and 24 hrs. The data obtained suggest an important role of the brain monoaminergic systems in the mechanisms of the HCK8 effect upon learning and memory.

5-Hydroxytryptophan↗
PubMedDate not supplied

[Influence of electromagnetic fields on the emotional behaviour of rats].

The effects of ultra low power pulse-width + modulation electromagnetic radiation (EMR, power density 10 mc/Wt/cm2, carrying frequency 915 MHz, modulating pulses with frequency 4, 6, 16 and 20 Hz, duration 10 min) on the rat emotional behavior and motor activity in the elevated plus-maze were studied. It was established that EMR (frequency of modulation 4 and 6 Hz) significantly decreased the emotionally negative reactions of anxiety and fear by a factor of 3.7 (p < 0.01) and 4.5 (p < 0.01) correspondingly and increased by a factor of 1.9-2.2 (p < 0.05) exploratory activity. On the contrary EMR (frequency of modulation 20 Hz) significantly increased by a factor of (p < 0.05) emotionally negative reactions of anxiety and fear and decreased by a factor of 1.8 (p < 0.05) the exploratory activity in rats.

Animals↗
PubMedDate not supplied

[Disruption of spatial memory in mice exposed to agroclavine].

The results of the study of the mnemotropic activity of the ergot alkaloid agroclavine are presented. Effects of this substance administered in doses of 1, 10, 25, 50, and 200 micrograms/kg on learning and spatial memory were studied in a Morris water maze. Agroclavine had no effect on learning but sharply impaired the retention. This memory impairment persisted for 48 h after the agroclavine administration. Agroclavine treatment did not affect the ability of mice to learn and retain a new skill. Possible mechanisms of the agroclavine effect on memory are discussed.

Animals↗
PubMedDate not supplied

[Immunodepressed status of mice after bulbectomy].

We studied the immune response in lymphoid cells of mice subjected to bilateral olfactory bulbectomy in comparison with sham-operated animals 1.5 and 13 months after surgery. The concentration of tumor necrosis factor decreased threefold in the peripheral blood of bulbectomized mice 1.5 months after surgery. Signs of immunodepression were also observed 13 months after surgery: suppression of mitogen-stimulated proliferation of T and B lymphocytes in the spleen, inhibition of synthesis of tumor necrosis factor in peritoneal macrophages and splenocytes, and decreased macrophage NO production. According to the immune status indices and our previous data on behavioral, biochemical, and morphological changes induced in bulbectomized mice, they have common symptoms with the Alzheimer's disease. This allows us to consider such animals as a model of sporadic form of this disease rather than of a depression.

Alzheimer Disease↗
PubMedDate not supplied

[Noopept improves the spatial memory and stimulates prefibrillar beta-amyloid(25-35) antibody production in mice].

The effects of the novel proline-containing nootropic and neuroprotective dipeptide noopept (GVS-111, N-phenylacetyl-L-prolylglycine ethyl ester) were studied on NMRI mice upon olfactory bulbectomy, which had been previously shown to imitate the main morphological and biochemical signs of Alzheimer's disease (AD). The spatial memory was assessed using the Morris (water maze) test; the immunological status was characterized by ELISA with antibodies to prefibrillar beta-amyloid(25-35), S100b protein, and protofilaments of equine lysozyme, which are the molecular factors involved in the pathogenesis of AD. The control (sham-operated) animals during the Morris test preferred a sector where the safety platform was placed during the learning session. Bulbectomized animals treated with saline failed to recognize this sector, while bulbectomized animals treated with noopept (0.01 mg/kg for 21 days) restored this predominance, thus demonstrating the improvement of the spatial memory. These animals also demonstrated an increase in the level of antibodies to beta-amyloid(25-35)--the effect, which was more pronounced in the sham-operated than in bulbectomized mice. The latter demonstrated a profound decrease of immunological reactivity in a large number of tests. Noopept, stimulating the production of antibodies to beta-amyloid(25-35), can attenuate the well-known neurotoxic effects of beta-amyloid. The obtained data on the mnemotropic and immunostimulant effects noopept are indicative of good prospects for the clinical usage of this drug in the therapy of patients with neurodegenerative diseases.

Alzheimer Disease↗
PubMedDate not supplied

[The characteristics of the anxiolytic action of taftsin and its analog TP-7 on behavior and serotonin metabolism in the brain of rats with chronic deprivation of serotoninergic system activity].

The effect of taftcine (Thr-Lys-Pro-Arg) and its analog TP-7 (Thr-Lys-Pro-Arg-Pro-Gly-Pro) on rat behavior and serotonin brain exchange was studied in 95 adult male Wistar rats neonatally administered with 5,7-dihydroxytriptamine. Intracutaneous administration of both peptides (300 micrograms/kg) was found to result in weakening perception of stress situations; an increase in stability of investigation behavior and normalization of serotonin level in the brain of rats with chronic deprivation of serotoninergic system activity. Anxiolytic and psychostimulant activities of TP-7 are more pronounced than those of tafcine.

5,7-Dihydroxytryptamine↗
PubMedDate not supplied

[Behavior reactions and lipids of brain synaptic membranes of rats under chronic exposure to gamma irradiation].

The effects of low level chronic ionising irradiation (12.9 cGy/day on the sensory attention to the stimuli of different modalities (somatosensory, visual, odor) of Wistar rats were studied. Analysis of animals behaviour was made after they had received the different doses of irradiation: 4, 6, 8, 10, 15 and 20 Gy. It was founded, that the attention and exploratory activity of rats is significantly decreased up to 20-30% after 4-6 Gy. The irradiation doses 8 Gy did not change animal behaviour as compared to control animals, but doses 10, 15 and 20 Gy decreased the exploratory activity as well as sensory attention of rats to 3-5-times as compared to previous dose. Such a wave-like way of behaviour reflects the functioning of an adaptive mechanism. Biochemical data indicated that after 5 months of the irradiation (dose 20 Gy) the level of phospholipids, lysophosphatidylcholine, phosphatidylethanolamine, phosphatidylcholine, cholesterol were decreased.

Animals↗