The effect of cerebral cortex isolation on sleep-wakefulness cycles in cats

It has been established in experiments with cats that the neuronal isolation of the cortex of a single cerebral hemisphere by the method of M. M. Khananashvili causes a disturbance in sleep duration for as long as four months. The character and completeness of the restoration of the sleep parameters indicates that the lost function of the cortex operated upon is gradually transferred to the cortex of the second hemisphere. It is concluded that there are no specific (internal) mechanisms in the cerebral cortex which regulate sleep. We make a suggestion on the basis of our own data and a number of works in the literature that the role of the cerebral cortex consists in regulating those internal brain processes which provide for adaptive sleep and wakefulness alternations during the course of uninterrupted internal and external conditions.