In experiments on 55 Meriones tamariscinus and 49 white rats the influence of D, L, alpha-tocopherolacetate on background activity of the sensorimotor and visual zones of the cerebral cortex of intact and castrated rodents was studied. Species and sex differences were revealed in animals reaction to vitamin E in doses commensurable with therapeutic ones. It is shown that tocopherol elicits a reduction of frequency and increase of amplitude of ECoGs in Meriones males and female white rats. After animal castration tocopherol action basically changes. It is suggested that the inhibitory effect of vitamin E on bioelectric processes in the cerebral cortex results from a change in the level of free-radical oxidation of lipid components of cellular membranes of cortical neurones due to an intensification of activity of their antioxidant system.