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Biomedical subjects

V V Andrianov

Publications and source records attributed to V V Andrianov.

At least 19 recordsLinked to original sources

Locomotor responses and neuron excitability in conditions of haloperidol blockade of dopamine in invertebrates and vertebrates.

Levels of movement activity were used to identify two groups of rats: those with high- and low-activity levels. Blockade of dopamine receptors with haloperidol led to suppression of locomotor activity in both groups of rats; in common snails, haloperidol decreased the rate of locomotion. The excitability of spinal centers in rats decreased 5 min after single i.v. injections, with gradual recovery seen by 30 min. Chronic administration of haloperidol suppressed post-tetanic potentiation of the H response in the gastrocnemius muscle of spinal rats. Prolonged use of haloperidol induced significant hyperpolarization of the membrane potential of command neurons in common snails and increased the action potential generation threshold. Selective pharmacological exclusion of the brain dopamine system was found to lead to decreases in the excitability of defined neurons in snails and the spinal motor centers in rats, also producing impairments in locomotor responses in these animals.

Animals↗

The effects of changes in extracellular calcium concentrations on the electrical properties of command neurons after acquisition of a defensive conditioned reflex in snails.

Studies of the electrical characteristics of the command neurons of a defensive reflex showed that the membrane potential showed no significant changes in response to changes in the calcium concentration in the perfusing solution in either intact or trained snails. Increases in the calcium ion concentration in intact snails were accompanied by increases in the threshold potential, from 14 +/- 0.7 mV at 2.5 mM Ca2+ to 21.8 +/- 0.9 mV at 20 mM Ca2+. The threshold potential in trained snails decreased in response to both increases and decreases in calcium concentrations, from 16.8 +/- 0.6 mV (physiological saline containing 10 mM Ca2+) to 13.3 +/- 0.6 mV at 20 mM Ca2+ and 11.8 +/- 0.8 mV at 2.5 mM Ca2+. The critical depolarization level changed correspondingly: in intact snails, this decreased with increases in calcium concentration, while in trained snails it increased in response to both increases and decreases in the calcium concentration.

Animals↗

Effect of chronic administration of chlorpromazine on electrical parameters of command neurons in edible snail.

Electrophysiological experiments showed that chronic administration of neuroleptic chlorpromazine depolarized plasma membrane and decreased the threshold of action potential generation in command neuron of defense behavior of edible snail and motoneurons of pneumostome closure reflex. The effects of chlorpromazine on electrical parameters of the identified neurons can be explained by its serotonin-depleting action.

Action Potentials↗

The effects of 6-hydroxydopamine on the electrical characteristics of snail neurons in long-term sensitization.

The effects of the neurotoxin 6-hydroxydopamine on the formation of long-term sensitization and changes in the membrane characteristics of identified neurons were studied. Injections of the neurotoxin 6-hydroxydopamine blocked the acquisition of long-term sensitization; when neurotoxin injections were given after the formation of long-term sensitization, they had no subsequent effect on conduction parameters. At the cellular level, recording of the electrical characteristics of common snail defensive behavior command neurons (LPa3, RPa3, LPa2, and RPa2) showed that the effects of 6-hydroxydopamine consisted of a small depolarization shift in the membrane potential and a change in the action potential generation threshold. Formation of long-term sensitization after injections of 6-hydroxydopamine did not lead to further decreases in the membrane and threshold potentials of command neurons as compared with snails only given injections of 6-hydroxydopamine. The changes in electrical measures of command neurons induced by administration of the neurotoxin 6-hydroxydopamine lasted at least two weeks.

Adrenergic Agents↗

[Sensomotor learning and heart rhythm dynamics under the conditions of monocular vision].

According to P. K. Anokhin's general functional system theory, integral behavior is considered to be realization of processes directed towards achieving a useful result. The subjects of the study were a number of students, whose ECG was recorded while they were trained to fulfill a visual-motor task. Successfulness of learning was estimated. The study demonstrated a connection between the heart rhythm dynamics and the level of learning to fulfill visual-motor tasks.

Adolescent↗

[Chemical plasticity of cerebral neurons in the dynamics of goal-directed behavior].

The main purpose of the study was to establish physiological regularities and neurochemical mechanisms of the participation of cortical neurons of cats in performance of food-seeking behavioral systemoquanta. The study shows that individual stages of food-seeking systemoquantum are characterized by different sensitivity of the visual cortex to neuromediators. The author considers combination of methods of functional neurochemistry and the theory of behavioral quantization to be advantageous in a certain way, because it reveals a possible association between neurochemical mechanisms of involvement of individual neurons and the stages of the development of behavioral systemoquantum.

Animals↗

[Locomotor reactions and excitability of neurons during the blockade of dopamine by haloperidol in vertebrate and invertebrate animals].

Two groups of rats with different level of motor activities: high- and low-active animals, were distinguished. The blockade of dopamine receptors by haloperidol led to depression of locomotor activity in both groups of rats; in grape snails, haloperidol caused a decrease of the velocity of locomotor responses. In was found that within 5 minutes of intravenous injection of haloperidol the excitability of spinal centers of rats decreased; but in 30 minutes in started restoring. Chronic application of the preparation depressed the effect of posttetanic potentiation of H-response in gastrocnemius muscle of spinal rats. In command neurons of grape snail, chronic injections of haloperidol causes a significant hyperpolarization shift of membrane potential and an increase of threshold of the generation of action potential. It was shown that the selective pharmacological inhibition of dopaminergic system of the brain led to a decrease of excitability in some determined neurons of the snail and spinal motor centers of rats, as well as inhibited the locomotor responses both in vertebrate and in invertebrate animals.

Action Potentials↗

Electrophysiological studies of the effects of 5,6-dihydroxytryptamine on the acquisition of a conditioned defensive reflex in snails.

The role of serotonin in the membrane properties of identified neurons was studied during acquisition of a conditioned defensive reflex. Serotonin deficiency was created using the neurotoxic serotonin analog 5,6-dihydroxytryptamine (5,6-DHT). Injection of 5,6-DHT was found to prevent decreases in the membrane and threshold potentials of command neurons during acquisition of the conditioned reflex as compared with snails given 5,6-DHT without training. Common snails recovered the ability to acquire the conditioned reflex two weeks after a second 5,6-DHT injection.

5,6-Dihydroxytryptamine↗

Membranotropic effects of antibodies to S100 protein in ultralow doses.

Two types of neurons exhibiting various reactions to application of antibodies against S100 protein in the washing solution were revealed in the nervous system of Helix lucorum snails. After treatment with antibodies against S100 protein the frequency of action potential generation decreased in spontaneously active B1, B3, B17, and PPa6 cells, but increased in B4 and B6 cells. The effect of antibodies against S100 was less pronounced in the solution of potentiated antibodies against this protein. After pre-exposure of ganglia in the solution of potentiated water the effect of antibodies against S100 protein decreased to a lesser extent. No significant changes were revealed in the membrane resting potential of cells. Combination treatment with antibodies and potentiated antibodies against S100 protein increased the threshold of action potential generation in B1 and B17 cells. Our results indicate that potentiated antibodies against S100 protein specifically modulate the activity of nerve cells.

Action Potentials↗

Effect of chronic haloperidol on electrical parameters of command neurons in Helix Lucorum.

We studied the effects of neuroleptic haloperidol on electric characteristics (resting potential, action potential threshold, and critical level of depolarization) of command neurons LPa3, RPa3, LPa2, and RPa2 responsible for defense behavior in edible snail Helix Lucorum. Chronic administration of haloperidol led to hyperpolarization shift of the membrane potential and increased the threshold of action potential in these neurons. The data indicate a new possible mechanism of sedative action of neuroleptics based on hyperpolarization of some cerebral neurons, in particular, neurons responsible for some behavioral functions.

Animals↗

[Effect of 6-hydroxydopamine on the electrical characteristics of snail neurons in long-term sensitization].

Studies of the influence of neurotoxin 6-hydroxydopamine selectively destroying the catecholamine terminals on long-term sensitization, and the role of dopamine in manifestation of characteristics of a membrane of identified neurons during elaboration of plasticity, were fulfilled. Injection of saline was used as the control. It is shown that preliminary injection of 6-hydroxydopamine reduces duration of long-term sensitization, but does not block it completely. It was shown that injection of 6-hydroxydopamine prevents diminishing of membrane and threshold potentials in withdrawal interneurons during formation of long-term sensitization. The experiments demonstrate that shift of electrical characteristics of withdrawal interneurons caused by injection of neurotoxin 6-hydroxydopamine to both naive snails and sensitized snails, statys during at least 10 days.

Animals↗

[Electrophysiological study of 5,6-dihydroxytryptamine effect on defensive reflex conditioning in the snail].

The role of serotonin in expression of membrane properties of identified neurons was studied during defensive reflex conditioning using the neurotoxic analogue of serotonin 5,6-dihydroxytryptamine (5,6-DHT). The defensive reflex conditioning in snails was destroyed on the second day after second injection of 5,6-DHT. Through the 1st weeks after second injection of 5,6-DHT the snails were learned but worse than snails after injection of saline solution. This result shows the recovery of snail's learning ability within 2 weeks after the second injection of 5,6-DHT. It was found that injection of 5,6-DHT prevented the decrease of membrane and threshold potentials of command neurons during defensive reflex conditioning as compared with the snails injected with 5,6-DHT without learning.

5,6-Dihydroxytryptamine↗

[Time course of changes in cardiac rhythms in successful and unsuccessful solution of visual and motor tasks under the conditions of binocular and monocular visions].

The P. K. Anokhin theory of the general functional system considers integral behaviour as realization of processes aimed at reaching a useful result. Electrograms were recorded in students who were solving visual and motor puzzle tasks. Their results were estimated. There were two groups of subjects: 1) those with normal binocular vision and 2) those with monocular vision. Some specific features were found in cardiac rhythm power in each group. The findings suggest that there are relationships between the results of task solution, the type of visual perception, and heart rate parameters.

Adult↗

[Polymorphism of virus-like particles of retrotransposons in Drosophila and yeast cells].

Data on the molecular arrangement of viruslike particles (VLPs) of yeast and Drosophila retrotransposons are presented. Two methods for identifying VLPs from specific retrotransposon families have been offered. The first method is based on VLPs fractionation by electrophoresis in agarose gel under strictly controlled conditions. VLPs of the Drosophila melanogaster retrotransposon families copia and gypsy and D. virilis retrotransposon Tv1 were identified by this method. The method based on heterologous induction of retrotransposons in cells of the mutant spt3 strain of Saccharomyces cerevisiae was used to identify VLPs of yeast retrotransposon Tyl and D. melanogaster gypsy retrotransposon.

Animals↗