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Biomedical subjects

N V Bobkova

Publications and source records attributed to N V Bobkova.

At least 19 recordsLinked to original sources
PubMed1997

Bulbectomy-induced loss of raphe neurons is counteracted by antidepressant treatment.

1. Bilateral olfactory bulb ablation was performed in C57B1/6j mice (C57). Separate groups of bulbectomized mice were treated with either antidepressants (trazodone, 20 mg/kg i.p., or amitriptyline, 20 mg/kg i.p.) or saline daily for 14 consecutive days starting 14 days after surgery. 2. Celloidine-imbedded 10 microns-thick brain sections containing the nucleus raphe dorsalis (NRD) or locus coeruleus (LC) were stained for Nissl, and the number of functional and pyknotic cells was counted out of 500 total cell count for each animal in every experimental group: sham-operated, bulbectomized treated with saline or one of the two antidepressants. 3. Bulbectomy produced a significant 4 times increase in the proportion of pyknotic cells in NRD as compared to sham-operated control. Both antidepressants reversed the effect bringing the number of pyknotic cells to control level. The proportion of pyknotic cells in LC was also slightly increased (61%) in the bulbectomized mice, but only amitriptyline was able to reverse the effect. 4. Widespread degeneration of the neurons in NRD caused by bulbectomy may be involved in the serotonergic component of the bulbectomy syndrome. The ability of antidepressants to diminish bulbectomy-induced loss of NRD neurons may underlie their restorative effect on the behavior and neurochemical characteristics of bulbectomized animals.

Amitriptyline↗
PubMed1994

Antidepressants suppress bulbectomy-induced augmentation of voluntary alcohol consumption in C57B1/6j but not in DBA/2j mice.

Bulbectomy has been previously shown to produce the specific antidepressant-sensitive syndrome in C57Bl/6j, but not DBA/2j mice. The present study examined the effect of the depression on voluntary alcohol consumption. Alcohol consumption and alcohol preference (% of alcohol solution in total liquid) in a free-choice, two-bottle situation was measured in C57BL/6j and DBA/2j mice after sham-operation, anosmia with 10% ZnSO4, or bulbectomy. Both anosmic and bulbectomized mice of both strains consumed more alcohol and showed stronger preference for alcohol than sham-operated mice. In DBA/2j mice both operations altered alcohol consumption of the whole population, and the effect of bulbectomy was stronger. In C57Bl/6j mice bulbectomy and, to a less degree, anosmia seemed to affect predominantly the low-drinking animals. Chronic treatment with antidepressants amitriptyline (20 mg/kg), trazodone (20 mg/kg), and imipramine (10 mg/kg), did not change alcohol consumption in sham-operated C57Bl/6j mice. In anosmic mice antidepressants decreased alcohol preference, but only amitryptyline also decreased alcohol consumption. All antidepressants decreased both alcohol consumption and preference in bulbectomized C57Bl/6j mice. In DBA/2j mice antidepressant treatment either increased, or did not alter alcohol consumption and preference in all groups, though the effects varied among individual antidepressants. The possible connection between the bulbectomy-induced behavioral syndrome and elevated ethanol consumption in C57Bl/6j mice is discussed.

Alcohol Drinking↗
PubMed1993

Effects of bulbectomy and subsequent antidepressant treatment on brain 5-HT2 and 5-HT1A receptors in mice.

The effects of bilateral olfactory bulbectomy on serotonergic 5-HT2 and 5-HT1A receptor binding were studied in the frontal cortex (FC), limbic structures (LS), including the hippocampus, amygdala, olfactory tubercule, and piriform cortex, and hypothalamus (HTH) in mice. Bulbectomy resulted in the increase of Bmax for [3H]spiperone binding with 5-HT2 receptors in FC in C57Bl/6j. The receptors in LS and HTH remained unchanged. Subchronic treatment of the bulbectomized mice with antidepressant trazodone (20 mg/kg/day, IP, 14 days) induced downregulation of 5-HT2 receptors in FC and LS. The other two antidepressants used, amitriptyline (20 mg/kg/day, IP, 14 days) and imipramine (10 mg/kg/day, IP, 14 days), did not alter these receptors. [3H]8-OH-DPAT binding with 5-HT1A receptors was not altered by bulbectomy in any brain area in C57Bl/6j mice. Amitriptyline and trazodone decreased Bmax for these receptors in FC in the bulbectomized mice while imipramine was ineffective. Amitriptyline and imipramine significantly increased Bmax and decreased Kd in HTH, and trazodone displayed the same tendency. Bulbectomy did not alter 5-HT2 receptors in DBA/2j mice. Amitriptyline increased Kd in the all brain areas without changing Bmax in the bulbectomized DBA/2j mice. Trazodone significantly decreased Bmax in FC and increased Kd in FC and LS. Imipramine decreased Bmax while increasing Kd in LS. The possible involvement of the serotonin receptor subtypes in the bulbectomy-induced behavioral deficits and in the restorative action of the antidepressants is discussed.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1992

Dissociation of multiple behavioral effects between olfactory bulbectomized C57Bl/6J and DBA/2J mice.

The behavioral effects of bulbectomy and subsequent antidepressant treatment in two mice strains were compared on measures of open field behavior and passive and active avoidance 2 and 4 weeks after surgery. After bulbectomy, both strains displayed elevated locomotion in open field, corrected by antidepressants. Enhanced rearing was decreased by antidepressants in C57Bl/6J, but not in DBA/2J mice. Passive avoidance, being intact 2 weeks after surgery in both strains, was strongly impaired 4 weeks after bulbectomy in C57Bl/6J mice, with antidepressants restoring the performance. Active avoidance acquisition and retention were also dramatically disturbed in C57Bl/6J mice 2 and 4 weeks after surgery, and antidepressants had recuperative effect. In contrast, bulbectomized DBA/2J mice didn't show any significant passive or active avoidance deficits, and antidepressant treatment seemed to have no effect on their learning ability. The observed strain differences suggest that bulbectomy may produce quite diverse neurophysiological and neurochemical alterations in two strains.

Amitriptyline↗
PubMed1989

[The role of the brain monoaminergic systems in the anti-alcohol action of dermorphin and the delta-sleep peptide].

The effects of dermorphin and DSIP were studied in male Wistar rats chronically treated with ethanol. Both peptides (200 mg/kg, i. p., daily during 10 days) significantly reduced volitional alcohol intake for 3-4 weeks. These effects were associated with a marked decrease in serotonin and its metabolite 5-HIAA levels in the hypothalamus. The findings suggest that antialcoholic effects of both peptides are actualized through mechanisms involving serotoninergic system of the brain.

Alcohol Deterrents↗
PubMed1988

[Effect of the active immunization of rats with a serotonin-protein conjugated antigen on the content of biogenic amines in the brain and on behavioral reactions].

Active immunization of rats with conjugated antigen serotonin-protein decreased the level of serotonin and its metabolite 5-hydroxyindole-3-acetic acid in some brain structures as well as the level of dopamine in the hypothalamus. The induction of antibodies to serotonin decreased the horizontal movement activity in the animals.

Animals↗
PubMed1986

[Monoamines and peptidergic Gomori-positive neurosecretory cells of the paraventricular nucleus of the rat hypothalamus in chronic alcohol consumption].

For 6 months the rats were kept on 20 degrees ethanol. Then, the rats could choose whether to drink alcohol (A) or water. The rats formed 2 groups: those preferring A and those preferring water. The control rats were kept on water. The function of hypothalamus monoamine- and peptidergic systems were disturbed following chronic A treatment. Alcohol-preferring, unlike water-preferring rats, have revealed higher hypothalamus levels of serotonin and lower levels of dopamine and noradrenaline, which correlated with changes in fluorescence intensity of hypothalamus noradrenaline structures and were accompanied by remarkable disturbances in nonapeptide neurohormone transport in the paraventricular nucleus region.

Alcohol Drinking↗
PubMed1986

[Increased efficacy of teturam combined with L-DOPA in experimental alcoholism in the rat].

In an experiment on Wistar male rats the authors studied the effects of teturam, diethyldithiocarbamate and Esperale in combination with L-DOPA on the consumption of alcohol and metabolism of biogenic amines in the brain. The use of L-DOPA prolonged the inhibitary effect of teturam on alcohol consumption. The administration of L-DOPA following Esperale implantation prevented the development of the abstinence syndrome. An increase in the efficacy of teturam and Esperale under the effect of L-DOPA was attended by elevated synthesis of cerebral noradrenaline.

Alcohol Deterrents↗
PubMedDate not supplied

Effect of repetitive stimulation on cortical single unit activity.

Activity of single units in the visual and sensomotor cortex of an uncurarized, unanesthetized rabbit was recorded by means of two independent microelectrodes during photic stimulation at different frequencies. Trace effects characterized by repetition of the temporal structure of afferent stimulation and by an increase in the level of intercellular correlation were discovered mainly on analysis of distant interneuronal relations after stimulation with frequencies of 2 and Hz. Stimulation at a frequency of 8 Hz did not evoke trace effects.

Animals↗
PubMedDate not supplied

Influence of local injection of 5,7-DHT and 6-OH-DA into the neocortex on learning and exploratory behavior of rats in the open field.

The features of the exploratory behavior in the open field, of the learning of a conditioned-reflex food-procuring reaction, and of the shift in the level of biogenic amines of the brain was studied in Wistar rats with local injections of the specific neurotoxins 6-hydroxydopamine (6-OH-DA) and 5,7-dihydroxytryptamine (5,7-DHT). It was shown that damage to the structure of the serotoninergic or catecholaminergic systems of the frontal cortex and hippocampus caused by local injection of 6-OH-DA and 5,7-DHT into the neocortex is accompanied by multidirectional changes in the exploratory behavior and learning of the animals.

5,7-Dihydroxytryptamine↗
PubMedDate not supplied

Influence of active immunization of rats with conjugated serotonin-protein antigen on the content of biogenic amines in the brain and on behavioral responses.

The influence of induction of antibodies to the neuromediator serotonin in the case of active immunization of animals with a conjugate serotonin-protein antigen on the distribution of biogenic amines in the brain and on behavioral responses was investigated in experiments on rats. It was shown that active immunization of rats with a serotonin-protein conjugate leads to a decrease in serotonin, its metabolite 5-hydroxyindole-3-acetic acid, as well as dopamine in certain brain structures. Against a background of induction of antibodies to serotonin, the horizontal motor activity of the animals is decreased.

Animals↗
PubMedDate not supplied

[Rearrangement of the spatial synchronization of the stratified activity of the cortex during the orienting response and upon stimulation of the nuclei of the brain stem reticular formation and mammillary bodies].

In experiments on alert rabbits it was shown with the help of correlational-spectral method that the rearrangement in the spatial organization of the activity of the first and the fifth layers in the visual and motor cortical zones during orienting reflex and high-frequency stimulation of reticular formation nuclei (NRP and NRT) is of the same type. The synchroneity in the activity of motor zone layers and the fifth layers of different areas increases in parallel. At the same time in the spectra of layer activity high-coherence theta-rhythm increases simultaneously. The data obtained permit to assume that specific rearrangement in the synchroneity of biopotentials of the studied layers during orientation reflex is due to influences of the reticular formation. The effect of mammillary bodies stimulation proved to be less effective.

Animals↗
PubMedDate not supplied

[The behavioral and biochemical sequelae of the removal of the olfactory bulbs in C57Bl/6j mice].

Ablation of the olfactory bulbs in mice C57Bl/6j was accompanied by motor and orienting-exploratory activity augmentation in the "open field" test and deterioration of the learning ability to active and passive avoidance. The most expressed behavioural changes developed in four weeks after the surgery. Chronic administration of antidepressants (amitriptyline, 20 mg/kg; trazodone, 20 mg/kg; imipramine, 10 mg/kg; intraperitoneally) normalized behaviour of bulbectomized animals, trazodone being the most effective. In the biochemical studies the brainstem serotonin level was found to be decreased and the density of 5HT2-receptors in the cerebral cortex increased in bulbectomized mice. Only trazodone was able to correct the biochemical indices. The state of the bulbectomized mice is supposed to serve a model of a depression with hypo-function of serotonergic system of the brain.

Amitriptyline↗
PubMedDate not supplied

[Effect of the local administration of 5,7-DHT and 6-OHDA into the neocortex on the learning and exploratory behavior of rats in an open field].

On Wistar rats characteristics were studied of investigating behaviour in the open field, of learning of conditioned food-reinforced reaction and also of BA and their metabolites content in various brain structures under local intracerebral injections of specific neurotoxins; 6-hydroxydopamine (6-OHDA) and 5,7-dihydroxytryptamine (5,7-DHT), abolishing correspondingly catecholaminergic and serotoninergic terminals. Bilateral injection of 6-OHDA in the neocortex led to a weakening of rats investigating activity in the open field and to an increase of the time of fulfillment of the forming of conditioned food-reinforced reaction. Administration of 5,7-DHT was accompanied by an increase of the investigating behaviour in the open field and a reduction of the duration of the forming of conditioned reaction. Administration of 6-OHDA to the neocortex caused a lowering of catecholamines level in the frontal area of the neocortex and the hippocampus. Analogous administration of 5,7-DHT elicited simultaneously with a deep level lowering of 5-HT and its metabolite in these structures, a change of catecholamines content which testifies to a lesser specificity of the neurotoxin 5,7-DHT in comparison with 6-OHDA. Structures lesion of serotoninergic and catecholaminergic systems of the frontal cortex and the hippocampus brought about by a local administration of 6-OHDA and 5,7-DHT in the neocortex was accompanied by differently directed changes in animals behaviour.

5,7-Dihydroxytryptamine↗