Increase of paradoxical sleep episodes after electrical stimulation of the lateral and third ventricles in the rat.

Electrical stimulation (0.3 mA in intensity, 80 Hz in frequency, 0.7 ms in signal duration) applied at 17.00 h in the lateral and third ventricles induced a significant increase of nocturnal paradoxical sleep (PS). This effect persisted for two consecutive days in both cases. Non-specific aspects involved in this effect are discussed and the results are commented on in terms of humoral processes and possible control of pineal gland activity.