[Functional connectivity of neurons of the frontal cortex and hippocampus under conditions of cholinergic deficit during choice behavior].

In cat experiments under conditions of choice between two different strategies of the instrumental behavior (impulsive and self-controlling), functional connectivity of neurons in the frontal cortex, hippocampus and between them was assessed on the basis of the analysis of wide and narrow peaks of cross correlation histograms of several spike series and their number. The functional connectivity of neurons in the above mentioned structures was better expressed in self-controlling cats than in animals with mixed impulsive/self-controlling reactions. On the contrary, the influence of an outer source assessed by the number of the wide peaks of cross correlation histograms was more pronounced in cats with mixed impulsive/self-controlling reactions.

[Cooperative neuronal activity of the n. accumbens and the frontal cortex in cats trained to choose stimuli of various value].

It was shown that the two-way interaction between neurons of the frontal cortex and n. accumbens progressively increases, whereas their regularity simultaneously decreases with the rise in impulsiveness and drop in self-control in behavior. In case of the long-latency instrumental reactions, a control of the frontal cortex neurons by neurons of the n.

[Organization of interneuronal relationships in the nucleus accumbens during impulsive and self-control behavior in cats].

Under conditions of a choice between a high-valuable delayed and a low-valuable immediate food rewards, cats were divided into 3 groups on the basis of their individual strategy of behavior: (1) choosing predominantly the high-valuable reward because of inhibition of the instrumental response (capable of self-control), (2) choosing predominantly the immediate low-valuable reward (impulsive), and (3) with a mixed pattern of reactions (ambivalent). Coherent activity of nucleus accumbens neurons which was a characteristic of interactions between nearby cells was assessed by the method of crosscorrelation. It was found that the total number of interneuronal interactions in cats capable of self-control exceeded that displayed by impulsive cats.

[Interrelations between neurons of the frontal cortex and hippocampus under cholinergic deficit in choice behavior of cats].

Appetitive instrumental conditioned reflexes on light (CS+) were formed in six cats by the method of "active choice" of quality of reinforcement; bread-meat mixture was given after short-delay conditioned bar-press responses, and the delayed responses were rewarded by meat. The animals differed in choice behavior strategy: "self-control", "ambivalent", "impulsive". The multiunit activity in the frontal cortex and hippocampus (CA3) was recorded.

[The individual organization of frontal-hippocampal networks during realization of different behavioral tasks].

Four cats were subjected to appetitive instrumental conditioning with light as a conditioned stimulus by the method of "active choice" of the reinforcement quality: short-delay conditioned bar-press responses were followed by bread-meat mixture and the delayed responses--by meat. The animals differed in behavior strategy: four animals preferred bar-pressing with long delay (so called "self-control" group); two animal preferred bar-pressing with short-delay (so called "impulsive" group). Then all the animals were learned to short-delay (1 s) instrumental conditioned reflex to light (CS+) reinforced by meat.

[Interaction between neurons of the frontal cortex and hippocampus during the realization of choice of food reinforcement quality in cats].

Six cats were subjected to the procedure of appetitive instrumental conditioning (with light as a conditioned stimuls) by the method of the "active choice" of reinforcement quality. Short-delay conditioned bar-press responses were rewarded with bread-meat mixture, and the delayed responses were reinforced by meat. The animals differed in behavior strategy: four animals preferred the bar-pressing with a long delay (the so-called "self-control" group), and two cats preferred the bar-pressing with a short delay (the so-called "impulsive" group).

[Organization of neocortical neuronal networks].

Multiple unit activity in deep layers of the frontal and motor cortices was recorded by chronically implanted semimicroelectrodes in waking cats with different levels of food motivation. From four to seven neuronal spike trains were selected from the recorded multiunit activity. Interactions between neighbouring neurons in the motor and frontal areas of the neocortex (within the local neuronal networks) and between the neurons of these areas (distributed neuronal networks) were estimated by means of statistical crosscorrelation analysis of spike trains within the range of delays from 0 to 100 ms.

[Cooperative activity of motor and frontal cortex neurons in trained cats systemically administered M-cholinoreceptor blockers].

It was shown previously that peripherally administered antagonists of the central 1 M-cholinoreceptors led to a selective impairment of bar-pressing response in a food-reinforced operant conditioned task but did not alter contextual behavior and functions such as motivation, perception, and locomotion. To obtain information about the central mechanisms of the conditioning impairment, we recorded simultaneously the extracellular multiunit activity from the frontal and motor neocortical areas of five cats trained to acquisition criteria in a food-reinforced operant conditioning task. Multiunit recordings were performed drur 1) normal conditioning; 2) conditioning during subcutaneous administration of muscarinic antagonists scopolamine (0.

[The role of muscarinic cholinoreceptors in the retrieval of the instrumental food conditioned reflex in cats].

It was demonstrated in cat experiments that impairment of the retrieval of appetitive instrumental conditioning observed after systemic administration of antagonists of muscarinic central cholinoreceptors scopolamine (a nonselective M1 antagonist) and trihexyphenidyl (relatively selective M1 antagonist) could be connected with central and peripheral side effects of these antagonists. It was established that in case of the absence of side effects (low doses of trihexyphenidyl, 1 mg/kg) the blockade of M1-cholinoreceptors led either to selective fall-off of the motor instrumental reaction with in the presence of contextual behavior and other conditioned reactions or the appearance of errors that seemingly was indicative of the disturbance of triggering and realization of the motor program as the most important component of conditioning performance. The systemic injection of trihexyphenidyl (10 mg/kg), scopolamine (0.

[Functional organization of local neuronal networks in the cat neocortex. Dependence on the food motivation].

The multiple unit activity (MUA) from clusters of adjacent neurones in deep layers of the frontal and motor cortex was recorded in alert cats with different levels of alimentary motivation. Up to 7 spike trains were selected from the MUA. Neurones in the local circuits could be divided into 2 groups: large neurones with prevailing divergent characteristics, and small neurones with prevailing convergent characteristics.

[The interrelations between neurons of the amygdala and hypothalamus during conditioning with selection of food reinforcement quality in cats].

Three cats were subjected to appetitive instrumental conditioning to light by the method of the "active choice" of the reinforcement quality. The short-delayed conditioned bar-pressings were reinforced by bread-meat mixture and the delayed response by meat. The animals differed in behavior strategy: two animals preferred bar-pressing with long delay (the so-called "self-control" group) and one animal preferred bar-pressing with short delay (the so-called "impulsive" group).

[Interneuronal frontal-amygdala interactions in cats trained for the quality of the reinforcement].

In eight cats the appetitive instrumental conditioned reflexes to light were elaborated by the method of "active choice" of reinforcement quality: the short-latency bar-pressing responses were reinforced with bread-meat mixture and the delayed responses were reinforced with meat. The animals differed in behavior strategy: six cats preferred the delayed pressings (the so-called "self-control" group), and two cats preferred the pressings with short delay (the so-called "impulsive" group). The multiunit activity in the basolateral amygdala and frontal cortex was recorded by chronically implanted nichrome semimicroelectrodes.

[Interneuronal relationships in the basolateral amygdala of cats trained for choice in the quality of food reinforcement].

The alimentary instrumental conditioned bar-pressing reflex was elaborated in cats by the method of "active choice" of either short-delayed reinforcement with bread-meat mixture of delayed more valuable reinforcement with meat. The animals differed in behavior strategy: some animals preferred bar-pressing with the long delay (the so-called "self-control" group), other animals pressed the bar with short delay (the so-called "impulsive" group). The multiunit activity in the basolateral amygdala was recorded with chronically implanted nichrome microelectrodes.

[The temporal organization of the interneuronal frontal-motor relations in the cat neocortex depending on the level of food motivation].

The multiunit activity in the frontal and sensorimotor cortex was recorded by the bundle of nichromic electrodes in waking cats with different levels of alimentary motivation. Interaction between the neighbouring and distant neurons was evaluated by means of statistical cross-correlation analysis of spike trains. It was shown that the 24-hour food deprivation increased the number of correlations between discharges of the neurons both in the local (between the neighbouring neurons in the frontal and sensorimotor areas) and distributed networks (interarea correlations between the frontal and sensorimotor cortical neurons) with delays in the range of 0-100 ms.

[The interneuronal functional connections in the sensorimotor cortex of dogs].

Multiunit activity of sensorimotor cortex was recorded from chronically implanted semi-microelectrodes in two dogs. Functional interneuronal connections between neuronal spike trains of 6-8 neurons selected from background multiunit activity were studied by the method of cross-correlation analysis. Bin widths 0.

[Interneuronal functional connections in the canine sensomotor cortex].

Multiple unit activity (MUA) of the sensomotor cortex was recorded from chronically implanted semimicroelectrodes in dogs. The spike trains of 6-8 neural units were selected from MUA. The character and temporal parameters of interneuronal functional connections were examined by the method of computerized cross-interval analysis.

[The conditioned avoidance reflex and intersignal movements: the correlation of the cardiac and motor components].

In five dogs correlation was studied of heart rate (HR) and motor component of conditioned avoidance reflex (CAR), elaborated by Petropavlovskiĭ method. Stable CAR was expressed in lifting and long (not less than 5-10 sec) holding of the paw on definite height (5-10 cm) for the avoidance of painful electrocutaneous paw stimulation in response to conditioned acoustic stimulus. The level of defensive excitation, evaluated by heart rate change was maximum before the beginning of the conditioned motor reaction.

[Multineuronal cortical activity in dogs with a defensive instrumental conditioned reflex].

By methods of correlation analysis, interrelations were studied of neurones with high, mean and low amplitudes of spikes singled out by amplitude principle from background multineuronal activity of the motor and somatosensory cortical zones, recorded by chronically implanted semi-microelectrodes in dogs. In trained animals, a high positive correlation was observed of singled out neurones discharges, particularly between the neurones with low and mean amplitude of spikes. By the method of cross-interval histogram, dependent relations were revealed of the neurones with different amplitude characteristic mainly of one-sided excitatory character.

[New data on the correlation of the cardiac and motor components of the instrumental conditioned defensive reflex in dogs].

Correlation of heart rate (HR) and conditioned motor reaction (CMR) was studied in dogs with conditioned avoidance reflex by the V. P. Petropavlovskiĭ method.

[Neurophysiologic analysis of the critical period of delay of a reinforcing stimulus in the dog].

At interval of less than 100 ms between indifferent sound and unconditioned electrocutaneous stimulation, classical defensive conditioned reflex is not elaborated in dogs, in full correspondence with literature data. But intracortical temporary connection is established; this fact is shown by electrographic phenomena, the most specific and demonstrative among them is "conditioned evoked potential". The absence of behavioural (peripheral) and presence of electrographic (central) manifestations allow to assume that for the formation of the conditioned reflex of full value the involvement is necessary of additional activational (motivational) mechanisms, connected with reticular and (or) limbic subcortical structures which do not react to the conditioned stimulus at time deficit in conditions of microdelay.

[Evoked auditory cortex potentials of wakeful dogs in response to paired clicks].

EP to a test click appears in the auditory cortex of alert intact dogs in 30--40 ms after the conditioning click (period of the so called absolute refractory state). The curve of the recovery of the second EP has a complex periodic character with two stages of complete recovery of the early EP complex amplitude: rapid initial after 80--180 ms, and final, 280--430 ms after presentation of the conditioning click.

[Evoked potentials of neocortical projection areas during short-delay defensive instrumental conditioned reflexes in dogs].

The elaboration of a defensive instrumental conditioned reflex with a short delay (only 1 s) to clicks (a series of 10 clicks, 0.9 c/s) leads to a considerable change in the pattern of EP in the auditory cortical area elicited by the first (conditioned) click of the series. A number of very late positive-negative oscillations appear, covering all the latency of the conditioned motor reaction (700-900 ms).

[Neuronal correlates of an alimentary instrumental conditioned reflex in rats].

Elaboration of an instrumental reaction of getting the food from a narrow tube with a defnite forepaw (handedness) brings about a distinct re-distribution of cellular activity in the motor cortex and in the caudate nucleus, contralateral to the instrumental paw. The changes were observed at a 250 msec. interval before and 512 msec.