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Results for “CONDITIONED REFLEX”

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At least 307 records · Page 17Linked to original sources
PubMed1979

[Incorporation of 3H-phenylalanine into the proteins of cerebral neurons and glia during elaboration of a defensive conditioned reflex].

The passive avoidance conditioning enhanced incorporation of 3H-phenylalanine into the total proteins of neurons and glial cells of CA3 hippocampus area and motor cortex, layer V. During the strengthening and maintenance of the reflex (6, 9, and 24 hrs after the learning session), turnover of proteins in the neurons and glial cells of CA3 hippocampus returned (rapidly in neurons, slowly in glia) to the level of active control. In the motor cortex, this decrease did not stop at the evel of active control: protein tureover decreased even below this level in all the cells after 9 hrs while in neuronal nuclei as late as after 24 hours.

Animals↗
PubMedDate not supplied

[Alteration of the slow cortical potential and neuronal activity during elaboration of conditioned reflexes in rabbits].

In experiments on alert rabbits it was shown that during the first blinking conditioned reflex to a sound, a slow negative potential appears in response to the conditioned signal in the auditory area of the cortex. At the cellular level, this correlates with the formation of polysensory neurone activity accompanied by a small increase in its action potential duration (generalization of excitation, depolarization). During stabilization of the reflex, its specialization, coordinative inhibition of other central responses related to narrowing of receptive areas, --a slow positive potential is evoked in EEG by the conditioned stimulus. At the cellular level correspondingly, a shift is observed from group discharges during intersignal periods to single rhythmic discharges in response to conditioned stimulation (concentration of excitation, lowering of excitability).

Action Potentials↗
PubMedDate not supplied

Appearance of functional connections between neurons resulting from changes in the frequency of their spike activity during the performance by animals of conditioned-reflex food-procuring responses.

Cats were conditioned to a food-procuring reflex to time. Correlation analysis was applied to multineuron activity in the motor cortex to study the functional connections between neurons with changing and constant instantaneous spike frequencies on performance by the animals of the passive waiting phase of the conditioned reflex, the number of functional connections between "areactive" neurons was smaller than that between "reactive" neurons; during the phase of active waiting, the numbers of functional connections become similar. The increase in the number of functional connections between "areactive" neurons during the active waiting phase appears to reflect an intensification of the analysis and processing of information, while changes in the functional connections between "reactive" neurons was regarded as allowing the possibility of correcting functional structures in the case of a rapid change in the situation or state of the animal.

Action Potentials↗
PubMedDate not supplied

[Formation of conditioned reflexes to a complex stimulus in the cat during early ontogeny].

Formation of conditioned reflexes to the simultaneous complex stimulus (light + tone) was studied in young kittens during the second and third months of their life. "Go-no-go"--paradigm was used. Kittens learned to differentiate between the complex stimulus versus its components. The rate formation of positive and inhibitory reflexes was compared in young kittens and adult cats. It was found that kittens were able to solve this task during the second and third months of their life. However, the formation rate of inhibitory reaction to different components of the complex stimulus increased between the second and third months.

Age Factors↗
PubMedDate not supplied

[Changes in the motor response threshold to direct electric stimulation of the motor cortex during elaboration of conditioned reflex switching-over].

During elaboration of switching-over of an alimentary salivary conditioned reflex to a defensive one in dogs, with foreleg passive flexion as a signal stimulus, excitability changes of opposite signs appeared in the cortical representation of the left foreleg. At the stage of elaborated switching-over, the threshold of the flexor reaction to a direct stimulation of the motor cortex became lower in the alimentary experimental situation (passive rise--milk) and rose in the defensive situation (passive rise--acid).

Animals↗
PubMedDate not supplied

Intralimbic evoked potentials during the formation of an alimentary conditioned reflex in response to the electrostimulation of the hippocampus of dogs.

Instrumental alimentary conditioned reflexes (CR) in response to the electrostimulation of the hippocampus were developed in experiments on dogs with electrodes implanted in various divisions of the hippocampus, the amygdala, the septum, and the hypothalamus. During their development the evoked potentials (EP) were investigated in the hippocampus itself and in other limbic structures, as well as in the hippocampus during the testing of the latter for the purpose of verifying generalization. The formation and extinction of the CR was accompanied by changes in the amplitude-temporal characteristics primarily of late components of the EP picked up from the lateral hypothalamus and the amygdaloid complex in response to the hippocampal electrostimulation. During the carrying out of this stimulation of signal functions (pedal pressing to obtain food), the average amplitude of the trace positivity and of the late negative wave were found to be lower than by the end of extinction in the presence of ineffectiveness of the signal. The average amplitudes of the late components of the hippocampal EP which arose in response to electrostimulation of the amygdala were lower in those tests in which the instrumental movement appeared when the generalization of the CR was tested.

Animals↗
PubMedDate not supplied

[New model for studying group learning in mice (synthesis of conditioned reflex and ethologic approaches].

In experiments on mice it has been shown that synthesis of conditioned reflex and behavioural approaches is advantageous for the more complete qualitative and quantitative characteristic of group learning and performance of conditioned avoidance reaction in rodents. The efficiency of group learning and performance of this reaction depend not only on the individual characteristics of animals (ability or inability to learning) but also on the type of hierarchic relationships in the group. The possibility is suggested to use this model for investigating the modulating effect of psychotropic agents on group learning and performance of avoidance reaction.

Aggression↗
PubMed1981

Generalization of the conditioned reflexes established by direct electrical stimulation of the hippocampus.

In four dogs instrumental defensive conditioned reflexes to direct electrical stimulation of the hippocampus were elaborated. After reaching 60 percent CR performance, unreinforced stimulations of several limbic structures were given to test generalization. Positive generalization was more frequent than negative one. The generalization effect changed considerably in the course of further conditioning, during which two main types of changes were observed. After repeated stimulations of additional points in the hippocampus, the septum and the limbic cortex, a strengthening of the generalization effect was observed, while test stimulations of the amygdala and the hypothalamus resulted in a gradual decrease of the generalization effect, including its complete disappearance.

Animals↗
PubMed1986

[Transfer of conditioned reflex hypoglycemia in dogs].

Conditioned hypoglycemia was induced by intravenous injection of a 20% glucose solution to donor dogs. In control tests the dogs were injected the same volume of 0.9% saline. Then 0.5 ml of cerebrospinal fluid from donor animals was injected into suboccipital cisterna of recipient dogs. 24 hours later the recipient animals were exposed to the conditioned signal and injected physiological saline. It has been demonstrated that hypoglycemic response in recipient and donor dogs was identical, the reactions retained in the recipient dogs for 5-7 days after the liquor administration.

Animals↗
PubMedDate not supplied

[The chaotic component of the high-frequency EEG of the rabbit cerebral cortex in the formation of a defensive conditioned reflex].

A chaotic component of high-frequency EEG of rabbits was studied in the course of defensive conditioning by non-rhythmical light stimuli with electrical reinforcement applied to the paw. The regular changes were demonstrated in the dynamic parameters of the EEG chaotic component. Characteristic changes were revealed in the values of attractor dimensions of the high-frequency EEG recorded from all the cortical areas under study both under the action of the conditioned stimuli and in the conditioning situation before presentation of stimuli pairings. The changes were observed in the afferent and efferent cortical parts of the conditioned arc as well as in the cortical areas, to which the conditioned stimuli were not directly addressed. The obtained data made possible to observe changes in the morpho-functional structure of the conditioned reflex at the cortical level in the process of conditioning. Substantial differences were revealed between the early and late stages of this process.

Animals↗
PubMedDate not supplied

[Pharmakologic analysis of the interrelationship between long-term and short-term memory in dogs with systems of conditioned reflexes].

It has been shown in experiments on dogs with elaborated integrated systems of conditioned reflexes (by Kupalov method) and choice reactions (by Hunter method); that the physiological mechanisms of short-term and long-term memory are not strictly isolated; they include some common biochemical structures and are interrelated. The action of amizyl or armin on the cholinoreceptors disturbs the short-term memory and some elements of the long-term conditioned memory: the duration of retention of traces from conditioned and unconditioned alimentary stimuli is reduced; regulation of the course of stabilized conditioned stereotypes is disturbed; differentiation and use of previous experience (extraction of data from long-term memory) are impeded.

Animals↗