Amygdaloid kindling during wakefulness and paradoxical sleep in the cat. 2. Sleep organization changes produced by...

The effect of daily electrical amygdaloid stimulation (kindling, K) during waking (W-K) and paradoxical sleep (PS-K) on sleep organization was tested in 2 groups of chronically implanted adult male cats. Animals were stimulated 3 h after the 8-h sleep recordings were begun. Percentage, total time, and mean duration and number of episodes of W, slow wave sleep I and II, and PS stages were determined. Also, the mean interval of occurrence and hourly accumulation of PS were assessed. Recordings were performed before, throughout, and immediately after kindling and 2 months after the last recorded kindled seizures. Analysis of total recording time demonstrated that in both W-K and PS-K animals the kindling process provoked only transitory changes which returned to baseline values during kindling and immediately after. Analysis of pre- and post-stimulation periods demonstrated compensatory changes in W and PS percentage during the late stages of kindling. We conclude that rather than sleep diminution, kindling provokes a circadian shift of W and PS stages.