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Results for “CONDITIONED REFLEX”

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[Electrophysiologic correlates of habituation and conditioned reflex elaboration].

The average correlation coefficient between the EEG of different parts of the cortex gradually decreases as the rabbit is habituated to the experimental surroundings. Elaboration of an electo-defensive conditioned reflex leads to its enhancement which is replaced by a phase of temporary decrease, to be followed again by an enhancement of EEG correlation. The pronouncedness of theta-frequencies in the spectral and coherent functions behaves in a similar way. Successive changes of delta-activity level reveal no regularity.

Animals↗
PubMedDate not supplied

[Spatio-temporal characteristics of the EEG of the cat during formation of a delayed conditioned reflex before and after lesioning the temporal neocortex].

Regular changes in dynamics of spatial distribution of single EEG theta-oscillations was revealed in experiments on 5 cats during elaboration of a delayed conditioned reflex, before and after the ablation of the neocortical temporal zones. The data point to an important role of cortical associative areas in the processes of learning and of brain damages compensation.

Animals↗
PubMed1980

[Relationship between background and induced activity of cat auditory cortex neurons during elaboration of a defensive conditioned reflex to acoustic stimulation].

Using glass microelectrodes, the impulse activity of auditory cortex neurons was studied in chronic experiments on cats. It was shown that an increase in frequency of the background activity occurring in many neurons during conditioning was often observed prior to the appearance of conditioned motor reactions. Comparison of mean frequencies of the background activity and corresponding evoked activity shows, on the one hand, the nonlinear dependence between them and, on the other hand, the prevalence of activation reactions as compared with inhibitory ones. Some levels of background activity were distinguished corresponding to mean evoked activity frequency ranges. Background activity analysis performed prior to the presentation of the conditioned stimulus and after its cessation (aftereffect) shows that at stable conditioned reflex mean frequencies in these periods are close to each other.

Animals↗
PubMedDate not supplied

[High-frequency components of cortical potentials and their phase-coherent characteristics during the acquisition of motor-food conditioned reflexes in dogs].

Phase-coherent characteristics of neocortex background electrical activity were studied in a wide frequency range (1-100 Hz) during interstimulus periods in the process of elaboration of motor alimentary conditioned reflexes in dogs. It was shown that the process of learning led to a considerable increase of the part of high (greater than 0.75) and significant (0.5-0.75) coherences, and also of small (0 +/- 15 degrees) and accounted (+/- 16 - +/- 30 degrees) phasic shifts as compared with the state of calm wakefulness. This increase lay mainly in the high-frequency range (40-100 Hz). The analysis of the interregional relations showed that they differed not only by values of phase-coherent characteristics, but also by distributions of the latter. The obtained data testify that the state of activation is manifested both in the rise of frequency of potentials oscillations and in the increase of their synchronization.

Animals↗
PubMedDate not supplied

[Inhibitory conditioned reflex of the tonic type].

Physiological parameters of dogs conditioned reactions were studied, elaborated in response to experimental situations stimuli: in one case the animals experienced painful electrocutaneous stimulation (defensive situation), in the other one--they did not (neutral situation). One of these reflexes, that appearing in the defensive situation, may be considered as positive, the other one (in neutral situation)--as inhibitory. In conditions of transswitching, positive tonic conditioned reflex (TCR) determines positive signal significance of phasic (trigger) stimulus and inhibitory TCR--the negative significance (of the same stimulus). By conditions of elaboration, the inhibitory TCR resembles two types of internal inhibition--differential and delayed inhibition. At the same time the inhibitory TCR differs in such an important property as long duration. It determines its special functional inhibition. It is assumed that in integral behaviour TCR (positive and inhibitory) is a conditioned mechanism of regulation of levels of wakefulness and emotional states.

Animals↗
PubMed1978

[Concentration of acid and basic proteins in the nuclei of hippocampal neurons and neuroglia of rat brain following elaboration of a passive avoidance conditioned reflex].

By means of two-wave-length visible cytophotometry, the content of acidic and basic proteins per cell nucleus was shown to increase in CA3 hippocampal neurons only 3 hours after the learning session of conditioned reflex of passive avoidance. The protein content in the nuclei of perineuronal neuroglia cells of CA3 hippocampus increased only 6 hours after the learning session. Biochemical mechanisms dealing with the process of learning are discussed.

Animals↗
PubMedDate not supplied

[High-frequency components of the electrical activity of the dog neocortex during formation of motor alimentary conditioned reflexes].

Power spectra of electrical activity of different dogs neocortical areas within a wide frequency band (1-100 Hz) were studied by correlation-spectral analysis during elaboration of motor (pressing the pedal) alimentary conditioned reflexes (CR) to acoustic stimuli. Considerable redistribution of autospectra power (ASP) within one of the five selected frequency ranges (from I to V, 20 Hz each) was observed. The frequencies of III-V ranges (41-100 Hz) were the most reactive; the degree of power increase after CR stabilization was determined by its initial level before CR elaboration which significantly differed in various animals. The weaker were presented in the EEG high frequencies before learning, the higher was the increase of their power in the process of elaboration of the given type of CR, and on the contrary, a definite level of "saturation" was preserved. Relatively low frequencies (below 20 Hz) were characterized after CR elaboration by lowering of the power. Deliberate lowering of the alimentary motivation led to a weakening of CR and power decrease (in comparison with stabilized CR) of all frequency components; however, its level remained higher, than before CR elaboration.

Animals↗
PubMedDate not supplied

Correlation relationships of evoked activity of the auditory cortex and the amygdalae of cats during conditioned reflex activity.

The character of the interaction (Spearman's correlation coefficient) between the structures before, and during the development, extinction, and restoration of an instrumental food-procuring reflex, as well as during the automatization of the reflex was determined on the basis of the averaged sound-induced activity (AEP) of symmetrical points of the auditory cortex (AI) and the amygdalae (abl) of cats. The co-tuning of the cortex and the amygdalae during the adaptation of the animal was found to be individual in character; this was replaced by close interactions during the formation of the reflex and by the disruption of their correlatedness during its extinction. The consolidation of the reflex prior to the stage of automatization was accompanied by attenuation of the connections between the cortex and the amygdala. The results attest to the complex and dynamic character of the interdependence in the cortex-amygdala system during conditioned reflex activity.

Amygdala↗
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[Spatial characteristics and the dynamics of the activation foci in the cortex during the elaboration of a conditioned reflex (thermographic research)].

In acute experiments on immobilized white rats, by thermovision methods and digital image processing, spatial distribution and dynamics of local heating and cooling of dorsal surface of the cerebral cortex was studied through intact skull during elaboration of a conditioned reflex. Distant and noninvasive thermovision methods allowed to reveal and quantitatively study local cortical thermal reactions in the somatosensory and motor cortex and in the cerebellum in the process of elaboration and testing of conditioned connection. Under discussion are mechanisms, properties and significance of these effects for investigation of learning.

Animals↗
PubMedDate not supplied

[Evoked potentials during the elaboration of a conditioned reflex to hippocampal stimulation in rats].

In experiments on 9 rats, the study of evoked potentials (EPs) of the CA1 field of the dorsal hippocampus to stimulation of its symmetrical part serving as a signal of drinking conditioned reflex (CR) showed that during reflex elaboration, the amplitude of the main EP components significantly decreased; CR did not appear when the population spike (PS) was absent in the hippocampal response. PS always accompanying CR was not specific only of it, it was also recorded at other behavioural reactions. Changes of fascia dentata EPs in the process of CR elaboration to stimulation of its symmetrical part consisted in decrease of the initial negative wave and increase of the positive one. The obtained data point to a significant reconstruction of excitatory and inhibitory inputs to the hippocampus and fascia dentata under the influence of conditioned activity.

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