Role of GABA-A receptor in the preoptic area in the regulation of sleep-wakefulness and rapid eye movement sleep.

The role of GABA in medial preoptico-anterior hypothalamic area in the regulation of spontaneous sleep-wakefulness and rapid eye movement sleep was investigated in this study. Local microinjection of picrotoxin, a GABA-A antagonist, into this area increased quiet wakefulness but significantly reduced deep sleep and rapid eye movement sleep. Both the frequency of generation and duration per episode of the latter were significantly reduced. It is concluded that GABA-ergic neurotransmission in the medial preoptic area is spontaneously active in modulating the hypnogenic function including rapid eye movement sleep and the action is mediated by GABA-A receptor.