Vesicular acetylcholine transport inhibitor suppresses REM sleep.

The vesamicol-like compound (+/-)-4-aminobenzovesamicol (ABV) non-competitively inhibits vesicular packaging of acetylcholine (ACh) in presynaptic terminals. This study tested the hypothesis that microinjection of ABV into the medial pontine reticular formation (mPRF) of intact, unanesthetized cats would inhibit rapid eye movement (REM) sleep. Microinjection of ABV alone or before administration of the acetylcholinesterase inhibitor neostigmine was used to evaluate the effects of ABV on natural REM sleep and on the neostigmine-induced REM sleep-like state. ABV decreased (24.8%) REM sleep and significantly reduced (33.6%) the neostigmine-induced REM sleep-like state. The results show for the first time that REM sleep generation can be disrupted by blocking a synaptic vesicle protein that modulates ACh transport in localized regions of the mPRF.