Characteristics of neuronal activity in prefrontal cortex during performance of spatial delayed reactions in monkeys.

Several types of neurons were differentiated on the basis of a study of neuronal activity in various parts of the cortex near the sulcus principalis during the execution of spatial delayed reactions by monkeys. It was established that the different types of neurons are represented in different numbers in different parts of the cortex near the sulcus principalis. The determination of several factors influencing the activity of these neurons and the comparison of data on their quantitative representation in the anterior, middle, and posterior parts of the cortex near the sulcus principalis with the existing behavioral data obtained after local ablations of identical regions of the brain made it possible to postulate that neurons belonging to the different types are involved in the analysis of different processes and represent different functional units.

Significance of emotional excitation in the mechanisms of spatial short-term memory in lower apes.

Correlates of variation in the level of emotional tension are studied in long-term experiments on adult monkeys. The simultaneous appearance of the electrodermal response and of a change in the heart rate is shown to reflect more accurately a rise in the level of emotional tension. Continuous recording of autonomic indexes reveals an increase in tension level during the presentation of conditioned signals and the performance of the motor response in the spatial delayed response test program. The emotiogenic structures are thought to influence the specific mechanisms of short-term memory during the presentation of conditioned signals and the performance of food-procuring instrumental behavior.

[Characteristics of the activity of prefrontal cortex neurons during spatially delayed reactions in the monkey]. / Kharakteristika aktivnosti neironov prefrontal'noi kory vo vremia ispolneniia obez'ianami prostranstvennykh otsrochennykh reaktsii.

On the basis of unit activity in the cortex around sulcus principalis during the spatial delayed response, several types of neurons were distinguished in monkeys. The number of different neurons varied in different parts of the cortex. Determination of some factors affecting the activity of these neurons and comparison of data on their quantitative distribution in the anterior, medial and posterior parts of the cortex around sulcus principalis with the available behavioral data obtained with restricted removal of the same brain areas, lend support to the assumption that the neurons attributed to different types are responsible for a variety of processes and represent various functional units.

[Participation of the posterior hypothalamus in the activity of the ascending activating system]. / Ob uchastii zadnego gipotalamusa v deiatel'nosti voskhodiashchei aktiviruiushchei sistemy

In chronic experiments on cats with premezencaphalic section of the brain stem electrica stimulation of the posterior hypothalamus caused desynchronization of the electrical activity of the neocortex. After the isolated injury of the posterior hypothalamus a moderate electrical stimulation of the medical part of the midbrain reticular formation failed to cause any pronounced activation of the neocortex. The results obtained indicated an important role of the posterior hypothalamus in the function of the ascending activating system.