Cooperative activity of neurons in the nucleus accumbens and frontal cortex in cats trained to select reinforcements of different value.

Results obtained at the level of the organization of interneuronal interactions of cells in the nucleus accumbens and frontal cortex revealed the features of the involvement of this component in "impulsive" and "self-controlled" behavior, consisting of an increase in bidirectional interactions between the structures of interest, accompanied by simultaneous reductions in the regularity of interactions with increases in "impulsivity" and decreases in "self-control." Long-latency reactions appearing only in "impulsive" animals were associated with decreases in the control of frontal cortex cells by the nucleus accumbens during the signal period, which correlated with the low activity of the network activity of the nucleus accumbens in these animals. Comparison of the patterns of frontal-accumbens interactions as the animals performed a single type of activity demonstrated that the connections in neuron pairs during the presignal and signal periods were similar, while significant differences in patterns were seen during the performance of different types of activity.

Organization of interneuronal connections in the nucleus accumbens in "impulsive" and "self-controlled" behavior in cats.

In behavioral experiments, cats placed in a situation of choosing between a high-value time-delayed and a low-value rapid food reinforcement elected to wait for the preferred reward (they demonstrated "self-control") or to obtain the worse reward quickly (they demonstrated impulsive behavior). On the basis of the selected behavioral strategy, the cats were divided into three groups - "impulsive," "ambivalent," and "self-controlled." Cross-correlation analysis was used to assess the linked activity of cells in the nucleus accumbens, which reflects the nature of interactions between close-lying neurons.

Intralimbic evoked potentials during the formation of an alimentary conditioned reflex in response to the electrostimulation of the hippocampus of dogs.

Instrumental alimentary conditioned reflexes (CR) in response to the electrostimulation of the hippocampus were developed in experiments on dogs with electrodes implanted in various divisions of the hippocampus, the amygdala, the septum, and the hypothalamus. During their development the evoked potentials (EP) were investigated in the hippocampus itself and in other limbic structures, as well as in the hippocampus during the testing of the latter for the purpose of verifying generalization. The formation and extinction of the CR was accompanied by changes in the amplitude-temporal characteristics primarily of late components of the EP picked up from the lateral hypothalamus and the amygdaloid complex in response to the hippocampal electrostimulation.

Role of the lateral and medial hypothalamus in the reproduction of alimentary and defensive instrumental reactions.

It was established in experiments on two dogs that a test electrical stimulation of the lateral hypothalamus reproduces an instrumental movement in the case of a developed alimentary instrumental CR to a tone and does not reproduce it in the case of a developed acid defensive instrumental CR. In the case of an electrical stimulation of the medial hypothalamus, the instrumental movement is essentially not reproduced, either in the alimentary or the defensive situations. The appearance of the instrumental movement with electro-stimulation of the LH in the alimentary situation is associated with activation of the backward conditioned connection from the motivational "alimentary" center of the LH to the representation of this movement in the motor cortex.

Role of the lateral and medial hypothalamus in the reproduction of the motoric reaction which is a signal during the development of classical conditioned reflexes.

It has been demonstrated in experiments on three dogs that test electrostimulation of the lateral hypothalamus reproduces the motoric reaction which is the signal stimulus during the development of classical alimentary CR (83%) and does not reproduce it during the development of classical defensive CR (93%). The test electrostimulation of the medial divisions of the hypothalamus, like the electrostimulation of the LH, reproduces the "signal" motoric reaction, but in a smaller percent of cases (62%), during the development of classical alimentary CR, and does not reproduce it during the development of classical defensive CR. The reproduction of the signal motoric reaction during the electrostimulation of the LH is associated with the activation of a backward conditioned connection from the motivational structures of the hypothalamus to the representation of the signal stimulus in the motor cortex.