[Electrographic manifestations of sleep in the neuronally-isolated cat cortex]

Electrographic manifestations of sleep were studied in the neuronally isolated cortex prepared after Khananashvili (1961). Development of electrographic sleep-waking manifestations in the neuronally isolated cortex depended on the time passed after cortex isolation. During the first weeks they were not clear, but after 4-6 months it was possible to record all the sleep-waking stages characteristic of the normal animals. During different sleep-waking stages the electrical manifestations in the neuronally isolated cortex occured simultaneously with the signs of sleep in the other, control hemisphere. Most prominent changes during all sleep-waking stages in neuronally isolated cortex occurred in the theta and delta bands, and the less prominent, in the gamma band. The ways of sleep activity propagation in the neuronally isolated cortex are discussed.