Increase in excitability of cortical nonspecific structures in the presence of a decreased level of influences from the brainstem reticular formation.

The results of the measurement of the threshold of electrical stimulation of the cortex sufficient to elicit the EEG activation reaction in the norm and under conditions of the reduction of influences from the brainstem of the reticular formation are presented. A decrease in the thresholds was observed in those conditions which are regarded as evidence of an increase in the excitability of the nonspecific cortical formations. The increase was uneven: it was maximal in the sensorimotor and minimal in the visual cortex. It is hypothesized that the data obtained in brain preparations with a decreased level of brainstem reticular influences may be applied to the understanding of certain phenomena of neurotic pathology in its neurophysiological aspect.