GABAA receptor agonist at the caudo-lateral peribrachial area suppresses ponto-geniculo-occipital waves and its related states.

PURPOSE:In order to explore the potential role of GABA, acetylcholine and glutamate in the caudo-lateral peribrachial area (C-PBL) over Rapid-Eye-Movement sleep (REM) onset and maintenance as well as on synchronized sleep with ponto-geniculo-occipital (PGO) waves (SP) in cats, a muscimol, carbachol and L-glutamate local application was performed and behavioral states were assessed. METHODS:Fourteen chronically implanted, adult, male cats underwent a 23 hour polysomnographic recording after 3 pharmacological manipulations: carbachol, muscimol and L-glutamate. Each cat received all three drugs randomly with a seven day interval. RESULTS:1) Carbachol increases waking, SP and REM sleep while decreases slow wave sleep (SWS). 2) Muscimol decreases SP percentage and number while increases REM sleep onset. 3) Carbachol facilitates PGO activity and increases the latency to both SWS1 and REM sleep but enhances PGO activity while muscimol decreases it. CONCLUSIONS:Acetylcholine promotes PGO related states (SP as well as REM sleep), while GABA reduces only SP and specifically PGOs.