Sleep-awake responses elicited from medial preoptic area on application of norepinephrine and phenoxybenzamine in free moving rats.

The study makes an attempt to find out the action of norepinephrine (NE) and phenoxybenzamine (PB), applied at medial preoptic area (mPOA), in altering the sleep-awake responses, in free moving rats, which has not yet been reported. Effects of application of NE during day and PB during night, at mPOA, on sleep-awake responses, were compared with application of saline during identical periods. Application of NE produced arousal, whereas, PB produced the opposite effect. The findings are suggestive of the involvement of NE terminals at mPOA in normal arousal.