[Shifts in the steady potential in the dynamics of stationary excitation of the cerebral cortex].

Shifts of steady potentials (SP) in the cerebral cortex of rats were studied during formation of stationary excitation foci by low-frequency electric stimulation and application of penicillin. The dynamics of SP shifts reflects summary effect of depolarization and hyperpolarization processes, actively involved in each cycle of excitation. As a result of functional heterogeneity of different cortical areas, a spontaneously appearing wave of spreading depression (SD) may be transformed into a spiral wave, actively influencing the dynamics of excitation resulting from direct stimulation of the cortex. The cause of long-term inhibition of paroxysmal activity foci may be repeated generation of slow negative waves of SD persisting in conditions of rapid restoration of cortical ability to conduct SD.