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Results for “CONDITIONED REFLEX”

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PubMedDate not supplied

[Effect of neurotizing exposures on conditioned reflex activity in the late postresuscitation period in rats].

In white rats resuscitated after 10-minutes stop of the blood circulation, conditioned switching over was elaborated on the basis of alimentary and defensive instrumental reflexes and the effect was studied of neurotizing influences. Single application of electrocutaneous pain stimulus in alimentary situation ("collision") led to more expressed disturbances of conditioned activity in resuscitated rats than in intact ones. Differentiation of a signal different from the positive conditioned stimulus only by the height of the tone, was practically not elaborated in resuscitated rats, and the disturbance of the conditioned alimentary reflex to the reinforced signal appearing during differentiation elaboration, was manifest in them to a greater degree. The obtained data testify that even a short-time brain ischemia, accompanied by a fast and full restoration of the neurological status, leads to functional defects of the CNS appearing at subsequent neurotic influences.

Animals↗
PubMed1992

[Role of glutamate intracortical connections in conditioned reflex activity].

The effects of iontophoretic application of glutamate and its blockers on neuronal activity of the sensorimotor cortex were studied in cat during fulfillment of conditioned instrumental placing reflex. 64 neurons were investigated. Application of glutamate caused reliable facilitation of neuronal impulse reactions to the conditioned stimulus. The facilitation appeared some seconds after beginning of the application of glutamate and continued for 5-10 min after cessation of the iontophoretic application. The similar inhibitory effect in neuronal activity was observed with application of APV, kinurenate, ketamine. It is suggested that the NMDA receptors under natural conditions take part in facilitation of the synaptic transmission in glutamatergic intracortical pathways.

2-Amino-5-phosphonovalerate↗
PubMedDate not supplied

[Conditioned reflex switching-over in the rat after temporary functional decortication].

Conditioned switching-over was elaborated in white rats: in one situation an alimentary instrumental reflex to sound was elaborated, in another one--an electro-defensive avoidance reflex to the same sound, different time of the day and different chamber illumination used as the switching-over factor. One-time influence of spreading depression by means of bilateral application of 10% KCl solution for 1.5 min to dura mater brought to the disturbance of the conditioned switching-over for 2-3 days. Electrolytic destruction of posterior hypothalamus area was produced in some animals. After restoration of functions one-time application of spreading depression elicited deep and long-term disturbance of conditioned switching-over. Apparently more complex conditioned activity suffers greater at short-term elimination of cerebral cortex functions, especially in conditions of compensatory recovery after lesions of the central nervous system.

Animals↗
PubMed1984

Comparative biology of mnemonic processes: conditioned defensive reflexes and conditioned immune reactions.

Analogies in considerable detail hold between essential characteristics of classical conditioned defensive reflexes and immune reactions. The analogies become evident when combined conditioned and unconditioned stimuli are formally set into correspondence with combined hapten and carrier immunogens. Learning is elaborated also in the immune system when the transfer of information from the unconditioned to the conditional immuno-stimuli concurrently occurs. The analogies are regarded as having been evolved by adaptation of fundamentally parallel functions for survival against attack or invasion in the course of evolution, one on the macro- and the other on the micro- or molecular scale.

Biological Evolution↗
PubMedDate not supplied

[Correlation of the neuronal impulse activity of different areas of the neocortex in rabbits in the switching of positive and inhibitory conditioned reflexes].

By cross-correlation method conjugation in impulse activity of pairs of simultaneously recorded units in the visual and sensorimotor areas of the neocortex (representations of the conditioned and unconditioned stimuli) was studied during the switching of defensive positive and inhibitory reflexes in rabbits. 30-second fragments of impulse activity were analyzed in intervals before and after three presentations of positive and inhibitory conditioned stimuli (CS). The activity of single pairs of units in the process of stimuli presentation was characterized by instability. Only in 29% of 51 units' pairs the presence or absence of correlation between their discharges was stable. Analysis of activity of 75 pairs of units showed differences in impulse activity in inhibitory and positive tonic reflexes. The number of pairs of correlated units in about 30 s after inhibitory CS decreased (27%) in comparison with the interval before its action (52%). In the inhibitory tonic conditioned reflex, temporal intervals of discharges of one unit correlated with discharges of the second unit undergo changes. The obtained results testify that such parameter as the number of pairs of units with correlated activity in intersignal time interval is very important for the realization of motor reaction to conditioned stimuli.

Animals↗
PubMedDate not supplied

[Dynamics of formation of water and food instrumental conditioned reflexes in freely moving dogs].

The dynamics of food and water conditioning was studied in freely moving dogs choosing the reinforcement. The dog's behaviour at any given moment was determined by the correlations of the excitability of the structures of the corresponding vital unconditioned reflexes. A directed change in the excitability of the structures of the unconditioned (alimentary and water) reflexes by raising or lowering the animal's excitability (hunger, satiation, thirst) resulted in a change of the animal's behaviour and its motivation. Goal directed movements of the animals are based on activation of backward conditioned connections.

Animals↗
PubMedDate not supplied

[Phenomenological model of changes in evoked potentials of the sensomotor area of the large cerebral hemispheres during processing of conditioned reflexes].

A phemenological model of variations in evoked potentials during conditioning is proposed. The model consists of four linear differentional equations. Variations in a wide range of only one parameter of the system of differential equations correspond to all variations in evoked potentials. A variation of this parameter in the presence of constant disturbances at the system input gives rise to the appearance of a constant or increasing signal at the output of the system, which is characteristic for the expectancy wave.

Cerebral Cortex↗