CHOLINERGIC NEUROTRANSMISSION, REM-SLEEP AND DEPRESSION

It is known from animal experiments that the regulation of REM and Non -REM sleep is governed by cholinergic and serotonergic/adrenergic neur ons in the brain stem. Cholinergic neurons in the gigantocellular fiel d of the tegmentum seem to be responsible for the triggering and maint enance of REM sleep. These findings are of special interest for interp reting abnormalities of REM sleep in depression. Psychiatric sleep res earch in the last two decades has demonstrated that an early onset of REM sleep and heightened REM density frequently occurs in patients suf fering from depression. Extrapolating from animal data on REM sleep re gulation, the premature onset of REM sleep in depression may be interp reted as the consequence of a central nervous cholinergic overactivity or muscarinic supersensitivity. In our experimental work we have test ed assumptions of the so-called reciprocal interaction model of NonREM and REM sleep by cholinergic/anticholinergic stimulation strategies o f sleep in healthy subjects. Furthermore, the impact of cholinergic st imulation on sleep in depression, healthy control subjects and other p sychopathological conditions was investigated. These studies demonstra ted that the most pronounced REM sleep response to cholinergic stimula tion occurred in depression.