“…These studies have shown that the application of Ach or cholinergic agonist, carbachol, into the brainstem induces REM sleep-like state in the cat. A number of studies from various laboratories confirmed, as well as expanded, those original cholinergic stimulation studies by inducing a REM sleep-like state in the cat via local microinjection of pharmacological agents that increase Ach by blocking its natural degradation or via activation cholinergic receptors in the mPRF (Amatruda et al, 1975;Baghdoyan et al, 1984aBaghdoyan et al, , b, 1987Baxter, 1969;Hobson et al, 1983;Kostowski, 1971;Quattrochi et al, 1989;Shiromani and McGinty, 1986;Vanni-Mercier et al, 1989;Velazquez-Moctezuma et al, 1989Yamamoto et al, 1990a;Yamuy et al, 1993). Microinjection of similar agents in rats also yields a comparative induction of a REM sleep-like state (Bourgin et al, 1995;Gnadt and Pegram, 1986;Kubin, 2001;Marks and Birabil, 1998;Shiromani and Fishbein, 1986).…”