Formation of Different Strategies of Competitive Foraging Behavior in Rats

We studied competitive interactions of rats during instrumental foraging behavior. Two groups of animals were revealed: rats with predominance of operant actions for getting food reinforcements (donors) and kleptoparasites that more often get food after instrumental acts of the partners. Intergroup differences began to appear and increased from 3-4 paired experiments. It was revealed that at the individual stage of learning the instrumental skill, donor rats were faster in learning and showed high foraging activity with shorter latency in comparison with kleptoparasites, which were initially slower and performed a large number of inter-signal actions in the form of unconditioned peeking into the feeder.

[Heart rate variability of subjects when the instruction reading and their interrelations with the effectiveness of the follow-visual-motor activities]

Investigation of the processes of studying human instructions relevant follow-up in terms of systemic mechanisms of learning and memory processes, and moreover affects such a fundamental issue as psychophysiology focused attention, understanding the meaning of the information provided and the formation of social motivation in human activities. Analysis of heart rate variability in reading the instructions compared to the initial state of operational rest showed that this stage of the activity causes pronounced emotional stress, which is manifested in increased heart rate, decrease in variability and pronounced changes in the spectral characteristics of heart rate. Besides, it was revealed that heart rate variability in a state of operational rest before testing, and in the process of reading instructions positively correlated with the duration of the instruction reading and inversely correlated with effectiveness and the level of resistance of the subjects to the error after error when follow-up activities. Showing pronounced gender differences in the relationships between changes in the variability of heart rate when reading the instructions and the subsequent execution indicators of visual-motor test.

Study of behavioral parameters during learning of rats in an operant feeding task and evaluation of biochemical indexes after dietary consumption of the phytoecdysteroid extract

Experiments on rats were performed to study the process of operant feeding learning, locomotor activity, oxygen consumption, and concentrations of corticosterone, β-endorphin, and prostaglandin E in blood serum after dietary treatment with the phytoecdysteroid extract. Administration of phytoecdysteroids was followed by the improvement of learning and increase in oxygen consumption and locomotor activity. Locomotor activity and oxygen consumption in the majority of control rats and phytoecdysteroid-treated animals were shown to be interrelated with the total locomotor activity and goal-directed operant behavior, respectively. No significant differences were found in the concentration of hormones in blood serum from animals of the control and treatment groups.

Role of serum renin and aldosterone in animal adaptation to high-altitude conditions

Adaptation to high-altitude conditions in rats with experimental renal failure is associated with shifts in the rennin-angiotensin-aldosterone system, which manifested in different serum levels of renin and aldosterone in response to water and salt loads depending on the stage of the compensation processes.

Dynamics of neuronal, autonomic, and motor measures in animals performing an acquired habit

Previously obtained results and data from other groups showing that intersignal activity in animals correlates with the success of acquisition of defensive and food-procuring behavior are presented. In addition, specific changes in neuron activity and in the dynamics of cardiac and respiratory activity are demonstrated during performance of intersignal behavioral acts. The moments of appearance of intersignal activity were studied, as were patterns of changes in neurophysiological measures during different types of intersignal actions. The first series of experiments showed that different contextual stimuli (mainly ratios of sector illumination, which are ethologically important for rats) have significant effects on the level of intersignal activity and the success of learning active defensive behavior. The next series of experiments, in which learning and extinction of a passive defensive habit in rabbits were performed, demonstrated the existence of two types of intersignal activity. The first type was characterized by repetition of pain reinforcement parameters in the structure of changes in neurophysiological measures during intersignal behavior; the second type was characterized by a coincidence of the whole structure of neuronal activity, cardiac rhythm, and respiration during intersignal activity with the dynamics of these measures during the conditioned reflex behavioral act. This study suggests that the process of intersignal extraction of an efferent program for acquired defensive behavior may be one of the mechanisms by which it is fixed in memory and plays an important role in the animal's achievement of useful adaptive results.

[The dynamics of neuronal, autonomic and movement parameters in animals during the reproduction of a learned habit]

Data by the authors, as well as from other laboratories, show that the intertrial responses correlated with accuracy of avoidance or feeding behaviour. Moreover our previously data demonstrated the definite changes of neuronal activity, heart rate and respiration during intertrial responses. In this study we investigated the time-course of intertrial response appearance, the pattern of neurophysiological parameters during intertrial periods, and the types of intertrial responses. Experiment 1 showed that different environmental stimuli influenced the level of intertrial responses and successfulness of the avoidance learning. In experiment 2, in which learning and extinction procedures were presented in rabbit passive-avoidance conditioning, two types of intertrial responses were observed; the first type repeated the pain reinforcement, the second one imitated the conditioned reaction of neuronal activity, heart rate, respiration, and moving. These investigations suggest that the processes of intertrial eliciting of avoidance effector programs may be one of the mechanisms of fixation in memory and play an important role in acquisition of more effective results.

[Characteristics of motor and cardiac activity in men during the performance of test "shooter"]

Subject's behavior and electrocardiogram were investigated during execution of the test "Shooter". Three kinds of strategies were used by subjects during the task performance. Three types of the motor activity of subjects were also found in the "interresulting" periods during the system activity. The spatial and temporal characteristics of these types of activity were similar to those during the actual achieving the result. Differences in the dynamics of the R-R-interval changes were found in the periods before achieving the positive or negative result.

Systems analysis of the neuroimmunological mechanisms of memory

Experimental data on the role of immunomodulators in the mechanisms of neurological memory are presented and assessed from the point of view of functional systems theory. It is demonstrated that the immunomodulator interleukin-1 beta and the alpha-2-interferon fragment RITLY improve the processes of learning and reproduction of an active defensive habit. These substances were found to have effects on the productivity of behavior, on orientational-investigative reactions, and on vocalization in response to a conditioned signal. A positive correlation between intersignal activity and productivity is demonstrated as a reflection of the mechanisms of anticipatory reorganization of behavior during learning. However, interleukin has a selective action depending on the ethological conditions obtained during learning.

[Typological features of cardiac regulation and emotional stress in man when achieving his results under test loads]

The relationship between heart rate and errors and work quality was studied in the examinees during somatosensory, mathematic, and Lindolt's tests. There was a significantly higher correlation between the time course variations of heart rate, the types of cardiac regulation (central, respiratory, autonomic), and the levels of the achieved. There was a basic difference between the groups of subjects in their responses to testing errors, by reflecting in altered heart rate and work quality.

[Systemic analysis of neuroimmune mechanisms of memory]

Administration of IL-1 beta and 125-129 fragment of alpha 2-interferon improved learning and retention of active avoidance behaviour in memory in rats. It also improved the correlation between intersignal runs and success of the avoidance behaviour learning. The data obtained suggest that an activation of the intersignal retention process is one of the mechanisms of the immunomodulators effect on learning and memory.

[Food-acquisition and avoidance behaviors: the role of immunomodulators in their systemic organization]

The experimental data concerning some aspects of neuroimmunology were analysed. The problems of likeness between immune and nervous systems (origin, functions, common substances, etc.) and particularly the participation of immunomodulators in the mechanisms of neural memory are under discussion. It was shown that administration of immunomodulator neurotropin (NSP) results in more steady consolidation and retention of feeding and avoidance behavior, and some neurophysiological mechanisms of that phenomena were revealed. Among them were the reorganization of neuronal interspike patterns in cortex and hippocampus; increasing the levels of vegetative (heart rate, respiration) and behavior parameters of learning during conditioning. Whole this complex of changes was retrieved during intersignal periods. The results suggest that one of the mechanisms of immunomodulators action on the learning and memory is the activation of reverberation processes in brain.

[The characteristics of the neurophysiological mechanisms of the acquisition and extinction of defensive behavior in rabbits under the action of the immunomodulator neurotropin]

Effects of neurotropin (NSP), a substance extracted from the inflammatory dermis of rabbits inoculated with Vaccine virus, on avoidance conditioning and extinction were studied in rabbits. Intravenous administration of NSP produced reorganization of the neuronal activity in CA1 area of the hippocampus making it more regular. Under the influence of NSP conditioned heart rate bradycardia became more expressed. NSP led to longer persistence of avoidance response during extinction. Under the action of NSP time patterns of intersignal neuronal activity, heart rate and respiration were similar to those during conditioning trials. The results suggest that NSP administration activates intersignal retention process which results in more steady consolidation of avoidance behaviour.

[The effect of the immunomodulator neurotropin on the learning of active defensive behavior by rats]

Rats were intraperitoneally injected with neurotropin (NSP), a substrate extracted from the inflammatory dermis of rabbits inoculated with Vaccine virus. Active avoidance behaviour of rats was studied. After NSP administration rats demonstrated higher levels of conditioning and true responses compared with control. In NSP-treated rats relationship between the time of beginning of intersignal run during learning and success of the avoidance trial differed from that in the control group. The results suggest that neurotropin administration activates the retrieval processes and leads to stronger consolidation of avoidance behaviour.