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PubMed1992

[The development of I. P. Pavlov's conditioned reflex theory].

This paper deals with the theory of Ivan Petrovich Pavlov (1849-1936), a Russian physiologist who presented for the first time the systematic theory of the function of the brain that controls the whole behavior of animals, i.e. higher nervous activity through experimental studies. This paper, principally based on Lectures on Conditioned Reflexes (1928), investigates the development of conditioned reflex theory from its beginning by dividing it into three periods. First, during the period from 1898 to 1906, the fundamental concept of conditioned reflex was established and the study of conditioned reflex became an independent discipline. From 1907 to 1916, the second period, Pavlov theorized on higher nervous activity on the basis of extensive data from his laboratory experiments of conditioned reflex. And Pavlov complemented conditioned reflex theory, during the third period from 1916 to 1928, and extended the boundaries of it through applications of conditioned reflex theory to psychopathology and typology. The study contributes to the understanding that conditioned reflex theory was historically developed, and not presented as a complete form from the beginning, and that Pavlov intended to study the higher nervous activity through the method of neurophysiology.

Animals↗
PubMedDate not supplied

[The interaction of a state of haloperidol-induced catalepsy and a passive-avoidance conditioned reflex].

Injection of haloperidol (2.5 mg/kg) immediately after elaboration of the passive avoidance conditioned reflex stabilized retrieval of the conditioned reflex on the 2nd, 7th, and 14th days. Catalepsy induced by haloperidol injection was increased after the completion of passive avoidance conditioning. Conditioned reflex retrieval decreased catalepsy which was retrieved without repeated haloperidol injection. In contrast to the control animals, in the animals after conditioning the most pronounced catalepsy was observed immediately after the conditioned reflex retrieval with the following stabilization at the lower level. The auto enhancement of catalepsy retrieval was more expressed on the 14th day (as compared with the 7th day) both in the control and learned animals, but in the latter it did not depend on the testing time (in contrast to the control animals.

Animals↗
PubMedDate not supplied

[Conditioned reflex switching over in unrestrained dogs].

Conditioned switching-over was studied in unrestrained animals by means of instrumental alimentary conditioned reflexes of pressing the pedal. A complex of auditory and spatial factors (start-ground) served as conditioned alimentary signal. Backward connections were stable and were manifested in the teturning of the animal to the start-ground after feeding. It has been confirmed that the observed working readiness is a conditioned reflex of a tonic type.

Animals↗
PubMed1991

[Conditioned-reflex food selection in mongrel white rats exposed to high temperature].

Under condition of normal temperature the conditioned reflectory runnings of rats on the audible irritants were developed more quickly during dry food than damp one. Daily influence of high temperature during two hours and partially water deprivation resulted in reduction of the conditioned reflex which had been developed before during dry food. The reproduction of the conditioned reflexes during dry food failed. The essential changings in the conditioned reflexes during damp and dry food were not found when animals had become overheating without restriction of water consumption. During daily heat affecting at the end of the second week animals adapted to high temperature. This statement is confirmed by lowering the rectal temperature, decrease of the breath rate, daily water consumption and restoration of the activity of conditioned reflexes.

Acoustic Stimulation↗
PubMedDate not supplied

Superconsolidated conditioned reflex--a highly adaptive system of behavior.

Superconsolidated (2500-3000 combinations), long-trained (two to three years), specialized (per I.P. Pavlov), instrumental alimentary conditioned reflexes were investigated in cats. It was demonstrated that such conditioned reflexes are unusually rapidly extinguished, despite the classical notion of extinction, according to which the more consolidated the conditioned reflex the more difficult it is and the longer it takes to extinguish it. Thus, in the very first experiment, stable extinction of the conditioned reflex commenced after two to seven (in different animals) presentations of the conditional stimulus without reinforcement, and 15-20 "zeros" in a row in relation to the conditioned reaction could be obtained. The rate of extinction essentially did not depend on the individual features of the animals or the level of alimentary motivation. The data obtained make it possible to set such reflexes apart in a special new category of conditioned reflexes, which apparently have a different neurophysiological and structural control base than the "younger" conditioned reflexes commonly studied in the laboratory.

Acoustic Stimulation↗
PubMedDate not supplied

[The effect of hippocampectomy on the acquisition and recovery of a conditioned reflex to time in rats].

The dynamics of time conditioning was studied before and after electrolytic lesions of the dorsal hippocampus in rats. Hippocampectomy disturbed the recovery of time conditioned reflex which was consolidated before surgery. The change depended on the extent of hippocampal lesion. In rats after the limited hippocampectomy the conditioned reflex recovered faster than in sham-operated animals. However, after more extensive lesions the process of conditioning recovery was delayed. In hippocampectomized animals without previous training the time conditioned reflex was not formed irrespective of the volume of brain lesion. Injection of amphetamine (0.05 mg/kg) was ineffective in this case.

Acoustic Stimulation↗
PubMedDate not supplied

Interaction of dominant focus and conditional reflex as a functional unit of behavior organization.

The interaction of two fundamental phenomena--the dominant focus and the conditional reflex--discovered and introduced by A. A. Ukhtomsky and I. P. Pavlov lay at the basis of behavior. According to E. A. Asratyan, the backward conditioned connection is a specialized dominant focus in the functional structure of the consolidated conditional reflex. It makes the behavior goal-directed and active. The dominant focus and conditioned reflex play the same role in the adaptive behavior of the individual as does variability and selection in the process of evolutional adaptation. That is why it is impossible to agree with Popper and Eccles that hypothesis theory has to replace Pavlov's theory of the conditional reflex. Imprinting and psychonervous activity by images (I. S. Beritashvili) are two special exemplars of conditional reflexes after one coincidence. The so-called "elementary reasoning activity of animals" (according to L. V. Krushinsky) is a kind of the instinctive inherited behavior.

Adaptation, Psychological↗
PubMedDate not supplied

[Analysis of the formation of systems of conditioned reflexes to time in rabbits].

Experiments on rabbits carried out by the food-procuring conditioned reflex method have shown that conditioned reflex systems to "pure" time can be elaborated, provided that conditioned stimulus is presented at regular, though different time intervals, following one another in a fixed sequence. The complexity of elaborating such systems to time is determined by the number of signal time intervals in the system, their different length, and their sequence. The formation of conditioned reflex systems to time is characterized by definite stages.

Animals↗
PubMedDate not supplied

[Forward and backward connections in instrumental drinking conditioned reflexes in rats].

Stabilization of instrumental drinking conditioned reflexes in rats is attended with a more frequent manifestation of backward connection. In response to the conditioned signal the first to appear is a classical conditioned reflex: the rat licks the drinking cup. This is followed by pressing the bar (manifestation of backward connection) after which the rat drinks the water (forward connection). When drinking, the rat tonically presses the bar (backward connection). During the rest of the session, phasic motor reactions prevail. Individual variations of frequency of backward connections manifestations were established in different rats.

Animals↗
PubMedDate not supplied

[Characteristics of cortical responses to electrostimulation of the internal geniculate body during formation of a defensive conditioned reflex].

During elaboration of a classical defensive conditioned reflex the dogs exhibited a dependence of the changes in amplitude and configuration of evoked potentials (EP) to electrical stimulation of the medial geniculate body (MGB), a conditioned stimulus, on the nature of effector manifestation of the conditioned reflex: the late components were the most depressed at multiple phasic reactions and not infrequently increased and became complicated at single and short motor reactions as well as at their incidental absence. The primary oscillations, while mostly remaining unchanged, were depressed in the case of conditioned reactions attended with a general motor restlessness. A difference has been revealed during conditioning in the EP changes to electrical stimulation of MGB and to an adequate peripheral stimulation. It has been assumed that EP changes during conditioned activity are determined by the relationship between the levels of tonic and phasic cortical activation.

Animals↗
PubMedDate not supplied

[Effect of polarization of different levels of the visual and motor analyzers on instrumental conditioned reflexes in dogs].

Dogs with stabilized instrumental conditioned reflexes of tonic form to a bell and flickering light, exhibited a depression or complete inhibition of the reflexes after a short anode polarization of the lateral geniculate body (LGB). Polarization of the superior colliculi exerted a similar influence but to a lesser degree. Prolonged polarization of the visual cortex completely inhibited conditioned reflexes to light at the very first or second minute of its action. The degree of inhibition depended on the current intensity, the area of its action and the functional state of the animal. Polarization of the sensorimotor cortex resulted in a delay and often in complete inhibition of the instrumental reflexes. Polarization of the red nucleus also inhibited the reflexes. Evoked potentials recorded from the LGB, the superior colliculi and the visual cortex underwent considerable changes (decrease of the primary response and disappearance of the secondary response) after polarization of the sensorimotor cortex.

Animals↗
PubMedDate not supplied

[Transfer phenomenon in alimentary conditioned reflexes of dogs].

Experiments on transfer phenomenon in alimentary conditioned reflexes of instrumental variety were carried out on dogs in stands and in conditions of unrestrained locomotion. In either experimental condition, after one of classical conditioned reflexes was changed into instrumental one, all conditioned stimuli started to elicit the unstrumental reflex without its special elaboration. If an instrumental reflex was initially elaborated to one stimulus, and then classical reflexes were elaborated to other stimuli, then these stimuli started to elicite the instrumental reflex as soon as they became alimentary signals.

Animals↗
PubMedDate not supplied

[Instrumental defensive conditioned reflexes to electric stimulation of the hypothalamus in dogs].

An instrumental defensive conditioned reflex to electrical stimulation of the lateral hypothalamus (LHS) was elaborated in seven dogs with electrodes implanted in different structures of the limbic system. Electrocutaneous stimulation was disrupted by a lift of the foreleg to a certain level. The conditioned reflex developed slowly: it appeared at the 15th to 35 th pairing, became stable by the 120--150th pairing of stimuli and reached a 60--90% level. Extinction of the conditioned reflex took 70--80 presentations of the conditioned stimulus without reinforcement. As LHS turned into a signal of electrocutaneous stimulation, the typical reactions to it weakened; in particular, searching movements and sniffing virtually disappeared, while licking movements appeared much more seldom both during the action of the conditioned stimulus and in the intervals between stimuli pairings.

Amygdala↗
PubMedDate not supplied

Effects of hippocampectomy on the development and recovery of a conditioned reflex to time in rats.

Experiments were carried out on rats to study the dynamics of recovery of a conditioned reflex to time after electrolytic lesioning of the dorsal hippocampus and the effects of hippocampectomy on the development of this response. Lesioning of the hippocampus deranged the restoration of a conditioned reflex to time which had been fixed before surgery. In conditions of limited hippocampal damage, the conditioned reflex to time recovered earlier than in sham-operated animals. Animals with more significant damage showed delays in the recovery of the response to time. After hippocampectomy without initial training, the conditioned reflex to time could not be developed regardless of the extent of damage to the hippocampus. This process was also not affected by doses of phenamine of 0.05 mg/kg.

Acoustic Stimulation↗