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PubMedDate not supplied

Kupalov's concept of shortened conditional reflexes: psychophysiological and psychopharmacological implications.

In the regulation of cortical excitability tonus, Kupalov described a particular acquired, learned mechanism, the shortened conditional Reflex (SCR). SCR is an essential mechanism by which an adequate cortical tonus is established by environmental cues as an anticipatory set-up preparing the individual qualitatively and quantitatively for expected forthcoming events. An original physiological example is given, the conditional "transfer" of motor behavior at cortical electrical stimulation. Three psychopharmacological implications are presented, namely environmental-dependent, stress-related events, environmental-dependent drug conditioning, and drug-tolerance experiments. Future eventual psychophysiological and psychopharmacological lines of research related to the shortened conditional reflex concept are discussed.

Animals↗
PubMed2006

[Genetically determined characteristics of conditioned reflex and locomotor activity of rats of different lines].

Peculiarities of conditioned instrumental food obtaining (getting) "pyrocmu" reflex development and realization of locomotor reactions (exploratory activity, motor activity, stance, gruming) of hypertensive (SHR) and Wistar rats in ordinary conditions and after strong sound signal were studied. It is shown that the dynamics of conditioned reflex development and its reproducing after experiment interruption are essentially different in two groups of animals: reflex conditioned in Wistar rats is of high level and is easily reproducible while in hypertensive animals it is transformed to the hidden (concealed) form of "incomplete" conditioned reflex-smelling at feeding rack in response to sound signal. The higher anxiety level and lower adaptability of hypertensive rats as compared with Wistar rats to the experimental conditions are confirmed by higher exploratory activity, more prolonged gruming in standard experimental conditions and long-duration immobility phase after sound signal.

Acoustic Stimulation↗
PubMedDate not supplied

[Mechanism of switching over simple and systemic conditioned reflexes to time in animals].

Switching over of simple reflexes and of a system of reflexes to "pure" time was studied on 12 rabbits, 2 dogs and one monkey. Instrumental conditioned reflexes (pulling a ring or pressing a pedal) were elaborated in response to 5; 4, 2 and 1.5 minutes time intervals; a system of conditioned reflexes was elaborated to different time intervals: 1.5--2.5--3.5 min and 4--2 min. Switching over agents were a metronome (300 beats/min), noise of a ventilator plus light of an electrical bulb, as well as different quantities or qualities of alimentary reinforcement. Turning in of the one and turning out of the other agents caused switching over of the food-procuring activity from one rhythm to another. The mechanisms of this complex form of integrative brain activity are discussed.

Animals↗
PubMed1984

[Integrative properties of parietal cortex neurons of rabbits during the switching of heterogeneous classical conditioned reflexes].

The impulsive activity of parietal cortex neurons of rabbits during the elaboration and specialisation of switching-over of alimentary and defensive conditioned reflexes has been studied. There are changes of parietal cortex neurons activity correlated with the stages of switching-over elaboration. The significant differences of the background neurons activity and neurons response to the conditional signal during alimentary and defensive conditioned reflexes have been established. The dominant motivation influences the neurons activity by modulation of background and conditioned activity of neurons. The integrative properties of neurons investigated in switching-over situation are revealed in their ability to summarize the excitation coming to the same sensory input with excitation from different motivational and reinforcement systems.

Acoustic Stimulation↗
PubMed2006

A possible mechanism for the effect of modifiable lateral inhibition in the striatum on the selection of conditioned reflex motor responses.

A mechanism is proposed for the effects of striatal dopamine-modifiable lateral inhibition on the selection of conditioned reflex motor responses. According to this mechanism, activation of dopamine D1 (D2) receptors on strionigral (striopallidal) neurons facilitates long-term depression (potentiation) of the inhibitory inputs simultaneously with potentiation (depression) of the excitatory inputs, of sufficient strength to open NMDA channels. For " weak" excitation, insufficient to open NMDA channels, the modification rules were of the opposite sign. Activation of presynaptic D2 (D1) receptors leads to decreases (increases) in GABA release from strionigral (striopallidal) axon terminals innervating strionigral (striopallidal) cells. As a result, dopamine-modifiable lateral inhibition simultaneously increases both the potentiation (depression) of the excitatory inputs to "strongly" activated strionigral (striopallidal) neurons, increasing (decreasing) their activity, and increases the depression (potentiation) of the excitatory inputs to the "weakly" activated strionigral (striopallidal) neurons, decreasing (increasing) their activity. Subsequent reorganization of neuron activity in the cortex-basal ganglia-thalamus-cortex circuit facilitates selection of conditioned reflex motor responses by further increasing (decreasing) the activity of those motor cortex neurons which were "strongly" ("weakly") excited by the striatum in conditions of dopamine release in response to the conditioned stimulus.

Animals↗
PubMedDate not supplied

[Radiation resistance of motor-defensive conditioned reflexes in rats at different stages of the formation and stabilization of a temporary connection].

Disturbances were studied of the motor defensive conditioned reflexes in rats radiated in a dose of 100 Gy at different stages of formation and stabilization of temporary connection. In comparison with consolidated (automatized) conditioned reflexes of active avoidance, early stages of formation and stabilization of the temporary connection are characterized by a relatively low resistance against extreme factors and by deepest disturbances of reproduction in radiated animals. The most probable mechanisms of these disturbances are connected with pathological changes of the nervous processes balance towards an increase of excitability and weakening of internal inhibition. Yet a direct radiation influence on the mechanisms of temporary connection reproduction at the second stage of its consolidation cannot be excluded. The role is shown of the emotional reactivity in the above-described processes.

Amnesia, Retrograde↗
PubMed1975

[Biochemical-genetic mechanisms of learning. II. Selection for a higher and lower rate of motor conditioned reflex acquisition].

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

[Monoaminergic component in the effect of D-9-tetrahydrocannabinol on conditioned reflex activity].

The involvement of monoaminergic system in the realization of the effect of D-9-hydrocannabinol on different parameters of the conditioned reflex was examined on cats. It appeared that the effect of D-9-cannabinol on the differentiation of long-term and short-term stimuli depends but to a different degree on the activity of both the serotoninergic and catecholaminergic systems. The effect of D-9-tetrahydrocannabinol on the rate of the performance of the conditioned reflex depends on the activity of the dopaminergic system.

Animals↗
PubMed2003

Activity of neurons in the pedunculopontine nucleus during a food-related operant conditioned reflex.

The activity of 91 neurons in the compact and diffuse zones of the pedunculopontine nucleus of freely mobile rabbits was studied during performance of a food-related operant conditioned reflex. A total of 37.4% of the neurons recorded showed reactivity to the conditioned stimulus, which is evidence that the pedunculopontine nucleus is involved in operant learning. A significant predominance of excitatory responses to the conditioned stimulus and to food reinforcement was demonstrated. The main patterns of cell responses were identified, these reflecting the nature of the effect of the conditioned stimulus on neuron activity, the structure of the behavioral act, and the properties of the reinforcement, and demonstrating a relationship between the pedunculopontine nucleus and the processes of attention, motor learning, and reinforcement. Differences were seen in the associative reactive properties of the compact and diffuse zones of the pedunculopontine nucleus to the conditioned stimulus and reinforcement, which is evidence for the functional diversity of this formation and suggests a leading role for the cholinergic compact zone in food-related operant learning and reinforcement, the diffuse zone having a leading role in food-related classical conditioned-reflex learning.

Action Potentials↗
PubMedDate not supplied

The role of muscarinic cholinoceptors in the retrieval of an operant food-related conditioned reflex in cats.

Experiments on cats showed that lesions affecting retrieval of an operant food-procuring reflex. occurring on a background of systemic administration of the centrally-acting muscarinic cholinoceptor blocker scopolamine (a non-selective M-cholinoceptor blocker) and trihexyphenidyl (a relatively selective M1-cholinoceptor blocker), might be associated with the central and peripheral side effects of these blockers, preventing performance of the conditioned reflex. It was established that when no side effects were present (low doses of trihexyphenidyl, 1 mg/kg), blockade of M1-cholinoceptors led to selective loss of the motor operant reflex while contextual behavior and other conditioned responses were retained or led to errors in performance of the reflex: this appears to be evidence that derangement of launching and performing the motor program is the most important component of the conditioned reflex. Systemic administration of trihexyphenidyl at a dose of 10 mg/kg, scopolamine at doses of 0.03 and 0.06 mg/kg, and the peripherally-acting non-selective blocker methylscopolamine at a dose of 0.03 mg/kg led to changes in the general functional state (disturbances in the emotional-motivational sphere), the extent of which depended on the individual sensitivity of the animal to the anticholinergic agents. The presence of side effects led to complete cessation of conditioned reflex activity, though this appeared not to be associated with memory impairment.

Animals↗
PubMed2006

Protein synthesis-dependent reactivation of a contextual conditioned reflex in the common snail.

We report here a study of the effects of blockade of protein synthesis with anisomycin during reactivation of a contextual conditioned reflex in the common snail. The amplitudes of the defensive reactions of snails to standard tactile stimulation before training were identical in two conditions: 1) testing of responses of snails fixed by the shell to a plastic ball floating in water and 2) on the surface of the terrarium glass. After applying electric shocks to the snails' skin for 5 days, a significant difference in responses reflecting the formation of a contextual conditioned reflex was seen in only one of the contexts. Placing trained snails in the same context (reminding) two days after training with simultaneous injection of anisomycin led to significant weakening of training, while control injections of physiological saline produced no such changes. These data suggest that the mechanisms of memory consolidation after training and reminding are not identical.

Animals↗
PubMedDate not supplied

[Comparative physiology of short-interval conditioned reflexes to time in different species of animals].

Conditioned reflexes (CR) to short time intervals (from 0.25 to 20 min) were studied in rabbits, white rats and pigeons by motor food-procuring method. Some significant distinctions between species were revealed. The mean duration of formation of CR to time in rabbits amounted to 74 pairings, in rats--to 121, in pigeons--to 217. The optimal time interval varied in rabbits from 2 to 10 min, in rats from 1 to 4 min and in pigeons in was from 1 to 1,5 min. The longest interval which allowed to form the trace CR to time was not in excess of 22 min in rabbits, 10 min in rats and 4-5 min in pigeons. The shortest interval was within 15-45 s. Unstable and incorrect CR to time was formed when the intervals were shorter or longer than the optimal one. The accuracy of CR to time was: in rabbits approximately equal to 0.93-0.95 in rats approximately equal to 0.85-0.94, in pigeons approximately equal to 0.78-0.85. The data obtained have satisfactory explanation in the light of I. P. Pavlov's hypothesis on physiological mechanism of CR to time.

Animals↗
PubMedDate not supplied

[Effect of a decrease in brain noradrenaline and serotonin levels on defensive and food-getting conditioned reflexes in rats].

The influence of pharmacological and surgical interferences in the activity of serotoninergic and catecholaminergic brain systems on elaboration and consolidation of conditioned reflexes was studied in rats. Ablation of the locus coeruleus, nucleus raphe and administration of inhibitors of monoamines synthesis reduced noradrenaline and serotonin (5-OT) content in rat's brain. Ablation of the locus coeruleus and disulphiram administration impaired mainly the elaboration of defensive and alimentary conditioned reflexes. Ablation of the nucleus raphe and parachlorphenilalanin administration affected predominantly the retention of the reflexes. At the same time, the effects of surgical and pharmacological interferences differed in some respects

Animals↗