Muscarinic Acetylcholine Receptors Chrm1 and Chrm3 Are Essential for REM Sleep

• Published in: Cell reports (Cambridge) 2018-08, Vol.24 (9), p.2231-2247.e7
• Main Authors: Niwa, Yasutaka, Kanda, Genki N., Yamada, Rikuhiro G., Shi, Shoi, Sunagawa, Genshiro A., Ukai-Tadenuma, Maki, Fujishima, Hiroshi, Matsumoto, Naomi, Masumoto, Koh-hei, Nagano, Mamoru, Kasukawa, Takeya, Galloway, James, Perrin, Dimitri, Shigeyoshi, Yasufumi, Ukai, Hideki, Kiyonari, Hiroshi, Sumiyama, Kenta, Ueda, Hiroki R.
• Format: Article
• Language: English
• Subjects: acetylcholine; Acetylcholine - metabolism; Animals; Chrm1; Chrm3; HEK293 Cells; Humans; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Receptor, Muscarinic M1 - metabolism; Receptor, Muscarinic M3 - metabolism; REM sleep; sleep; Sleep, REM - genetics; Tet system; triple-target CRISPR; TrkA; tTR
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2018.07.082

Sleep regulation involves interdependent signaling among specialized neurons in distributed brain regions. Although acetylcholine promotes wakefulness and rapid eye movement (REM) sleep, it is unclear whether the cholinergic pathway is essential (i.e., absolutely required) for REM sleep because of redundancy from neural circuits to molecules. First, we demonstrate that synaptic inhibition of TrkA+ cholinergic neurons causes a severe short-sleep phenotype and that sleep reduction is mostly attributable to a shortened sleep duration in the dark phase. Subsequent comprehensive knockout of acetylcholine receptor genes by the triple-target CRISPR method reveals that a similar short-sleep phenotype appears in the knockout of two Gq-type acetylcholine receptors Chrm1 and Chrm3. Strikingly, Chrm1 and Chrm3 double knockout chronically diminishes REM sleep to an almost undetectable level. These results suggest that muscarinic acetylcholine receptors, Chrm1 and Chrm3, are essential for REM sleep. [Display omitted] •Inhibition of TrkA+ cholinergic neurons causes a severe short-sleep phenotype in mice•Knockout of the muscarinic acetylcholine receptors Chrm1 and Chrm3 reduces NREM sleep•Knockout of Chrm1 and Chrm3 reduces and fragments REM sleep, respectively•Chrm1 and Chrm3 are essential for REM sleep The acetylcholine pathway has been proposed to be important for wakefulness and REM sleep, but genetic evidence has been missing. Using a knockout of acetylcholine receptor genes, Niwa et al. show that Chrm1 and Chrm3 double knockout chronically diminishes REM sleep to an undetectable level and causes a severe short-sleep phenotype.