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PubMedDate not supplied

Identification of Drosophila mutant with memory defects after acquisition of conditioned reflex suppression of courtship.

Four lines were selected from a collection of 33 lines prepared by P insertion mutagenesis using a single-copy P-element system; the males of these four lines showed memory defects after acquisition of conditioned reflex suppression of courting. In two lines (P171 and P95), the dynamics of retention of the conditioned reflex in the repeated impregnated-female courting test were similar to those of known short-term memory mutants dnc and rut. In line P153, the dynamics were more reminiscent of the memory dynamics in a known medium-term memory mutant, amn. In line P124, the learning index was insignificant immediately after training was completed, which may indicate that this line was unable to acquire conditioned reflex suppression of courting. Determination of the positions of the P elements (P171: 48A-B; P153: 49B-C; P124: 67B-68A; P95: 77C-D) showed no correspondence with previously known mutations producing memory lesions.

Animals↗
PubMedDate not supplied

[Dopaminergic modulation of impulse activity of sensorymotor cortex neurons during conditioned reflex].

Changes of conditioned impulse reaction of cortical neurons wer studied during microiontophoretic application of agonist and antagonists of glutamate and GABA transmission and their modulation by dopamine. It was shown paradoxal reaction of facilitation of impulse activity during iontophoretic application of ionotropic glutamate antagonist and depressive influences of metabotropic antagonist. Local iontophoretic application of dopamine increased background and evoked impulse activity of pyramidal neurons of deep layers of cortex and eliminated inhibitory influences of glutamate metabotropic antagonist MCPG. It is concluded that DA has stabilizing effects on activity of cortical neurons. It is suppose that these effects of DA realize through system of inhibitory interneurons.

Animals↗
PubMedDate not supplied

Influence of extirpation of the sensorimotor area of the cortex on the formation of conditioned reflexes in response to a complex signal in the ontogenesis of the cat.

The influence of the extirpation of the sensorimotor cortex (SMC) on the formation and maintenance of a previously developed alimentary conditioned reflex to a simultaneous complex stimulus (light + sound) with extinction of the reaction to unreinforced components of the complex signal was studied in kittens aged 39 days to 4 months. The extirpation of the SMC prior to 2.5 months of age had no influence on either the formation or maintenance of the conditioned reflex to the complex signal developed prior to the operation. The extirpation of the SMC in preliminarily trained kittens aged 3.5 months and older leads to disinhibition of the differential components when the positive conditioned reflex to the complex signal is maintained. In untrained kittens of the same age the extirpation of the SMC was manifested in the animals' incapacity to inhibit the motoric reaction to the differential signal. The question of the role of the SMC in ontogenesis during the formation of adequate forms of behavior which require the achievement of intersensory interactions is discussed.

Acoustic Stimulation↗
PubMedDate not supplied

[Conditioned reflex analysis of functional connections between the hippocampus and limbic system structures].

Instrumental defensive conditioned reflex elaborated in dogs to stimulation of the dorsal and ventral hippocampus, also appeared, due to generalization, in response to stimulation of a number of limbic structures. Two types of changes in the generalization effects (estimated by parameters of motor conditioned reaction) were observed in the course of conditioned reflex stabilization: enhancement (in response to stimulation of the lateral hypothalamus, lateral nucleus of septum, limbic cortex) and weakening toward complete disappearance (in response to stimulation of the medial nucleus of amygdala and medial hypothalamus). Manifestation of the generalization phenomenon from the brain structures, which are not involved initially into conditioned activity, suggests the existence of close functional connections between these structures and the hippocampus.

Amygdala↗
PubMedDate not supplied

[Improvement in the retrieval of a system of conditioned reflexes elaborated during rat ontogeny and administration of ACTH4-7].

A chain of two conditioned reflexes was elaborated in prepubertal rats from 2 to 6 weeks of age. Then the nature of amnesia was studied after an interval of 2 weeks. The system of motor food-procuring conditioned reflexes, disturbed by the interval was reestablished almost completely by ACTH4-7 administration before testing. A deficit of retrieval is supposed to be the cause of amnesia in prepubertal rats. Analysis of erroneous movements during the restoration of motor skill showed that information less essential for food getting suffered to a greater extent and it was not restored by ACTH4-7 administration. The retrieval disturbance did not depend on the degree of stability of the motor skill and the age of its acquisition.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

The discovery of the principles of reinforcement, extinction, generalization, and differentiation of conditional reflexes in Pavlov's laboratories.

The discovery of reinforcement, extinction, generalization, and differentiation with the conditional reflex method in Pavlov's laboratories is described. Modern American introductory texts show that contemporary understanding of the experimental work on conditioning in Pavlov's laboratories is derived from a 1927 English translation of Pavlov's lectures on the conditional reflexes. The lectures present the discoveries topically, not chronologically. In contrast, this article presents a chronological account of the contributions of S.G. Vul'fson, I.F. Tolochinov, and B.P. Babkin, which led to the conceptualization of reinforcement and extinction, and the work of V.N. Boldyrev and N.A. Kashereninova, which led to the formulation of the concepts of generalization and differentiation. This historical approach avoids giving the impression that the development of the Pavlovian paradigm was a highly systematic pursuit.

Animals↗
PubMed2005

The interaction of a new motor skill and an old one: H-reflex conditioning and locomotion in rats.

New and old motor skills can interfere with each other or interact in other ways. Because each skill entails a distributed pattern of activity-dependent plasticity, investigation of their interactions is facilitated by simple models. In a well characterized model of simple learning, rats and monkeys gradually change the size of the H-reflex, the electrical analog of the spinal stretch reflex. This study evaluates in normal rats the interactions of this new skill of H-reflex conditioning with the old well established skill of overground locomotion. In rats in which the soleus H-reflex elicited in the conditioning protocol (i.e., the conditioning H-reflex) had been decreased by down-conditioning, the H-reflexes elicited during the stance and swing phases of locomotion (i.e., the locomotor H-reflexes) were also smaller. Similarly, in rats in which the conditioning H-reflex had been increased by up-conditioning, the locomotor H-reflexes were also larger. Soleus H-reflex conditioning did not affect the duration, length, or right/left symmetry of the step cycle. However, the conditioned change in the stance H-reflex was positively correlated with change in the amplitude of the soleus locomotor burst, and the correlation was consistent with current estimates of the contribution of primary afferent input to the burst. Although H-reflex conditioning and locomotion did not interfere with each other, H-reflex conditioning did affect how locomotion was produced: it changed soleus burst amplitude and may have induced compensatory changes in the activity of other muscles. These results illustrate and clarify the subtlety and complexity of skill interactions. They also suggest that H-reflex conditioning might be used to improve the abnormal locomotion produced by spinal cord injury or other disorders of supraspinal control.

Animals↗
PubMedDate not supplied

[Analysis of changes in the electrical activity of the neocortex in dogs during the formation of the stereotype of food-procuring conditioned reflexes in them].

A system of food-procuring conditioned reflexes (dynamic stereotype after I.P. Pavlov) was elaborated in dogs. In the interstimuli periods, 0.6 to 0.8 sec. prior the action of the conditioned stimulus, they exhibited a "state of expectancy" characterized by an increase of frequency (up to 80 per sec.) of potential oscillations of a small amplitude (20 to 30 mcv) and their pronounced sychroneity, predominantly in the anterior parts of the neocortex. The conditioned signal acting against such background produced specific reactions in the form of a limited number of bursts (3 to 4 in 0.5 sec.) of highfrequency (up to 100 per sec.) synchronized activity (HSA) of considerable amplitude (50 to 60 mcv) which always preceded conditioned reactions, being in certain temporal relations with them. A correlation-spectral analysis has shown that in the HSA period, electrical activity became considerably more regular; in the intensity spectra the extreme frequencies of the analyzed band (5 to 7 c/s and 90 to 100 c/s) became prominent, and in most cases high values of the coherence function were due to them. HSA reactions are regarded as a major link in the trigger mechanism of conditioned food-procuring reactions.

Animals↗
PubMedDate not supplied

[An EEG-study of participation by the head of the dog caudate nucleus in alimentary conditioned reflex activity].

It was shown during alimentary conditioning in dogs that in the "background" electrocaudatogram there are rhythms typical of the act of eating, which become more clearly pronounced under the action of the conditioned stimulus. The EEG of the caudate nucleus head sharply changed during discordance reactions. It has been assumed that the caudate nucleus head forms a link in the functional system of the alimentary conditioned reflex at stages of afferent synthesis and functioning of the action acceptor.

Animals↗
PubMed1975

[The biochemical-genetic mechanisms of learning. II. Selection for high and low rate of acquiring a motor conditioned reflex].

Using the model of feeding motor conditioned reflex, polymorphism for the rate of the formation of this response was found in a population of laboratory animals. Selection for high and low rate of the formation of this reflex resulted in significant differences inthis character between two strains already in the second generation. These differences are maintained in subsequent generations. The existing henerogeneity for the rate of the formation of conditioned rsponse in the population is shown to be genetically determined.

Conditioning, Operant↗
PubMed1975

[Biochemical-genetic mechanisms of learning. II. Selection for high and low rates of acquiring a motor conditioned reflex].

Using the model of feeding motor conditioned reflex, polymorphism for the rate of the formation of this response was found in a population of laboratory animals. Selection for high and low rate of the formation of this reflex resulted in significant differences in this character between two strains already in the second generation. These differences are maintained in subsequent generations. The existing henerogeneity for the rate of the formation of conditioned response in the population is shown to be genetically determined.

Animals↗
PubMedDate not supplied

[Cortico-subcortical systems of conditioned reflex activity].

Experimental data are presented on dynamic rearrangment of corticofugal influences on subcortical structures during conditioning and conditioned performance, as well as data on the transition of diffusive influences, to selective ones. The mechanisms of plastic rearrangment of subcortical influences in the course of consolidation of the conditioned reflex are discussed on the basis of cortical-reticular and cortical-striate interactions. The significance of subcortical interactions in the integrative brain activity and in the organization of behaviour is discussed. Facts are presented on synchronization of several rhythms in rhythmical activity in the strio-thalamo-cortical system in the process of achievement of conditioned reflexes.

Brain↗
PubMed1981

[Changes in the sign of the response of striopallidal neurons during elaboration of conditioned reflexes to time].

During formation of motor conditioned reflexes to time (CRT) in alert rabbits, an increase in the number of neurones with activation and diminution of the number of cells with inhibitory trace activity was revealed when the stimuli were omitted, as compared with conditioned reactions (CR) to actual stimuli pairings, as well as a change in CR and CRT signs, as compared with the sign of cell responses to control tests. The changes were more pronounced in the caudate nucleus and the putamen. In the caudate nucleus and the globus pallidus, the number of cells capable of CRT in omissions of pairings increased as compared with the number of neurones which elaborate CR to actual pairings. Differences in the CR and CRT signs may suggest a difference in mechanisms of consolidation and reproduction of trace processes during elaboration of a motor behavioural act.

Animals↗
PubMedDate not supplied

[The acceleration of the acquisition of a conditioned reflex to time in rats with destruction of the suprachiasmatic nuclei of the hypothalamus].

In male rats sound conditioned reflex with water reinforcement was gradually (within 14-16 daily training sessions) was replaced by a conditioned reflex to time. After the bilateral lesions of the suprachiasmatic nuclei of hypothalamus, the necessary level of timing performance was reached sooner than in the animals with a partial destruction of the nuclei.

Acoustic Stimulation↗
PubMedDate not supplied

[Disorders in conditioned reflex activity and morphologic changes in the brains of rats deprived of paradoxical sleep].

Reproduction of defensive conditioned reflexes elaborated before a 96-hour deprivation of paradoxal sleep (DPS) in rats was sharply disturbed immediately after DPS, but became normal 24 hours later. Elaboration of conditioned reflexes immediately after DPS is followed by a disturbance of their reproduction, while such elaboration 24 hours after DPS does not affect their subsequent reproduction. It is assumed that dissociated learning plays an important part in the origin of the disclosed disturbances of conditioned activity. Morphological investigation of the animals' brain immediately after DPS revealed activation of neuroglia with productive-dystrophic changes of astrocytes, an increase in the sizes of nuclei of neurones in the motor cortex and hippocampus, and pronounced vascular changes. A day after DPS the changes of the astrocyte glia and the vessels are less pronounced, and the sizes of neurone nuclei in the motor cortex diminish.

Animals↗