RHYTHMIC ENZYME CHANGES IN NEURONS AND GLIA DURING SLEEP.

Rhythmic changes occur in the activities of enzymes in both the neurons and neuroglia isolated from the caudal part of the reticular formation of rabbits killed during sleep and wakefulness. During sleep, enzyme activity is high in the neurons and low in the glia; during wakefulness, this situation is reversed. In the oral part of the reticular formation rhythmic enzyme changes occur only in the neurons. No rhythmic changes occur in the hypoglossal and trigeminal mesencephalic neurons and glia. These findings indicate that the caudal part of the reticular formation reflects in metabolic changes the biological clock behind the sleep rhythm.