Effects of the selective activation of 5-HT3 receptors on sleep: a polysomnographic study in healthy volunteers

The respective role of various classes of central serotonin (5-HT) receptor s in the regulation of sleep-wakefulness cycles has been the subject of man y studies. Notably, it has been reported that 5-HT1A/B receptors are involv ed in the regulation of rapid eye movement sleep (REMS) and that 5-HT2A/C r eceptors participate in the control of slow wave sleep (SWS), but the role of 5-HT3 receptors is less well characterised. In this study we investigate d the effects of SR 57227A, a potent and selective 5-HT, agonist, on the sl eep EEG of normal young male volunteers. SR 57227A (2.5, 5, 10, 20, 40 mg o .d. and 20 mg b.i.d.) or placebo were administered during 7 consecutive day s in seven groups of ten subjects using a parallel group design. Sleep EEG recordings were performed on days 6 and 7 after all habituation session. SR 57227A produced a dose-dependent shift of REMS toward the end of the night without changing REMS and SWS duration nor altering sleep continuity. It s uggests a role for the 5-HT, receptor in the human sleep-wakefulness cycle and particularly in REMS regulation. (C) 2001 Elsevier Science B.V. All rig hts reserved.