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Biomedical subjects

R I Kruglikov

Publications and source records attributed to R I Kruglikov.

At least 19 recordsLinked to original sources
PubMed1990

[Effect of conditioned-reflex bilateral avoidance learning on lipid components of the rat brain].

The active avoidance training of rats resulted in a depletion of lipid peroxidation (LPO) products in cerebral cortex. LPO inhibition was also shown in cerebral cortex of "active control" group receiving +non-combined stimuli (the effect of short-term stress). LPO inhibition was more pronounced in rats staining a training criterion compared to rats which received combined stimuli but did not reach the criterion. In the active control group LPO inhibition was accompanied by total phospholipids accumulation and cholesterol depletion in cortical lipid extracts. Irrespective of attaining the criterion in all rats trained for active avoidance the accumulation of cholesterol was seen. Active avoidance training affected also the phospholipid composition of cerebral cortex.

Animals↗
PubMed1988

[Decreased chemoreactivity of neurons of the sensorimotor cortex during adaptation to stress and its role in the prevention of heart fibrillation in acute ischemia].

The effect of the adaptation to repeated short-term stress on the bioelectrical responses of neurons in the IV layer of the sensorimotor cortex developed under the action of acetylcholine and norepinephrine was studied in rats along with the effects on the development of arrhythmias, fibrillation and mortality in conscious animals with cardiac ischemia. It has been established that the preliminary adaptation reduced considerably the chemoreactivity and especially adrenoreactivity of the neurons and at the same time decreased fibrillation and mortality in acute ischemia.

Acetylcholine↗
PubMed1988

[Participation of beta-endorphin in the regulation of the membrane chemoreactive properties of the cortical neurons in rats].

The subcutaneous administration of beta-endorphin and its endogenic accumulation in the process of elaboration of adaptation to the short-term stress influences is accompanied by the change of chemoreactive properties of rat sensorimotor cortex neurons expressed in increasing of the share of areactive cells and lowering of the share of cells reacting by the response activational form to acetylcholine and noradrenaline led to them microiontophoretically. The reaction intensity of cells, both activational and inhibitory forms to the led neurotransmitters in both experimental groups is significantly lower than in control. The revealed changes of chemoreactive properties of neurons, arising under the influence of the increase of beta-endorphin amount in brain may be one of the mechanisms of its participation in the processes of learning and memory.

Acetylcholine↗
PubMed1987

[Changes in the protein level in rat hippocampal neurons during development of the alimentary conditioned reflex under normal conditions and after treatment with iproniazid].

The protein content in neurons of areas CA-1 and CA-3 of the dorsal hippocampus has been determined by means of cytointerferometry in rats during elaboration of unlocal alimentary instrumental reflex (ULAIR) and local alimentary instrumental reflex (LAIR) on the background of increased and normal serotonine content in the brain. It has been found that during the ULAIR elaboration the hippocampal neurons react by an increase of dry mass, during the LAIR elaboration-by its decrease. Under condition of serotonine excess in the brain the changes of dry mass in hippocampal neurons during elaboration of the two reflexes are opposite to these observed during the ULAIR and LAIR elaboration with normal serotonine content.

Animals↗
PubMed1985

[Effect of desglycine-arginine vasopressin on the excitability of the command neurons of the defensive reflex in the edible snail].

Perfusion of the snail (Helix lucorum L.) CNS with DG-AVP (concentration 10(-6) M) in the course of low frequency intracellular stimulation (2-4-minute interval) of the defensive reflex command neurons led to an increase in the excitability. It was expressed both in the reduction of the spike generation latency, in the increased number of spikes in response to fixed stimuli, and in the activation of pacemaker potentials. If DG-AVP was added to the medium during endoneuronal habituation, there was no increase in the excitability. It is supposed that modification of the neuronal excitability may be caused by the DG-AVP effect on the pacemaker mechanism.

Action Potentials↗
PubMed1985

Relationship between the release and uptake of noradrenaline by rat brain synaptosomes in the formation of defensive conditioned reflex.

The defensive conditioned reflex with two-way avoidance was developed in rats in a shuttle-box. Immediately and 30 min after learning the animals were decapitated and synaptosomes were isolated from the whole brain and brain cortex. Using [14C] and [3H]-noradrenaline (NA), the processes of uptake, spontaneous and potassium depolarization-induced (60 mM KCl) release of NA by brain synaptosomes of trained and control animals were studied in vitro. Immediately after learning the inhibition of NA uptake was observed, but 30 min following learning the ability of synaptosomes to take up NA was recovered to the initial level. Thirty minutes after learning the potassium depolarization-induced release of NA previously taken up by synaptosomes increased as compared to the control. NA spontaneous release did not change under these conditions. With the increase of Ca2+ concentration in the incubation medium from 1.2 mM to 2.4 mM, the induced NA release from brain synaptosomes of trained and control animals regularly increased. Changes in NA release and uptake are specific for the development of conditioned reflex

Animals↗
PubMed1985

[Effect of vasopressin and enkephalin analogs on the chemoreactive properties of the sensorimotor cortex neurons in rats].

On immobile rats it has been shown that subcuteneous injection of two different neuropeptides causes different distribution of activating, inhibiting and areactive cells resulting from microionoforetically administrated acetylcholine and noradrenaline without altering the mean frequency of the background unit activity sensorimotor cortical neurons. At the same time the alteration in the pattern of neurons impulse activity has been revealed, which acquires the character of packet activity with a specific packet length of 2-3, 4-6, 7-10 impulses. Depending on the injected neuropeptide reliable but almost contrary effects of the packet activity alterations have been observed. These effects have been suggested to result from the alteration of the chemoreactive properties of the neuron membranes and the corresponding reorganisations of interneuron attitudes.

Acetylcholine↗
PubMed1984

[Mechanisms of enkephalin action on learning and memory processes].

The influence of enkephalin on the processes of elaboration and preservation of the defensive conditioned reflexes of bilateral avoidance (CRBA) and conditioned reflexes of passive avoidance (CRPA) in intact rats and animals with changed functional state of serotoninergic system of the brain has been examined. Injection of enkephalin in dose of 10 mkg to intact animals accelerated the elaboration of CRBA not influencing in this case their preservation, but deeply disturbed the CRPA preservation. The excess of serotonin in the brain created by means of 5-oxytryptophan fully prevented the acceleration of CRBA elaboration by enkephalin under the usual conditions. Injection of enkephalin at the background of serotonin lowering and raising in the brain favoured CRBA preservation. Under the enkephalin influence the inclusion of [3H]tyrosine and [14C]lisine in water-soluble and water-insoluble proteins of different cerebral structures lowered. The obtained data testify to participation of serotoninergic system and brain proteins in the mechanisms of enkephalin action to the processes of learning and memory.

5-Hydroxytryptophan↗
PubMed1983

[Effect of the antioxidant ionol on the formation and retention of a defensive conditioned reflex during maximum physical exertion].

Administration of the synthetic antioxidant ionol to male Wistar rats prevents the disturbance of the conditioned reflexes during extreme physical load, induced by treadmill running. Protective action of ionol was marked by the improvement of the formation of the arising conditioned relations and their enforcement "till refusal" under maximal physical load. The possibility of antioxidant application to preventing the disturbances of the higher nervous activity is discussed.

Animals↗
PubMed1983

[Effect of a vasopressin analog on the chemoreactive properties of sensorimotor cortex neurons].

Subcutaneous injection of 10 micrograms desglycilargininvasopressin (DG-AVP) does not alter the mean frequency of background unit activity of sensorimotor cortical neurons. However, the pattern of impulse activity is essentially changed. At the same time the reactions of sensorimotor cortical neurons to microiontophoretic administration of acetylcholine and noradrenaline experience definite changes. It is suggested that the DG-AVP-induced changes in chemoreactive properties of neurons underlie the effect of this peptide on the learning and memory.

Acetylcholine↗