Paradoxical or REM sleep characterized by cortical activation combined with muscle atonia and rapid eye movements has been discovered at the end of the fifties by Michel Jouvet and William C. Dement. The studies of the next twenty years suggested that the onset and maintenance of paradoxical sleep is due to a reciprocal inhibitory interaction between brainstem monoaminergic neurons inhibiting PS (PS-off neurons) and cholinergic neurons generating PS (PS-on neurons) localized in a small nucleus of the pontine reticular formation named sublaterodorsal tegmental nucleus. In my talk, I will review our most recent studies indicating that the key PS-off and PS-on neurons are in fact GABAergic and glutamatergic. Further, I will show that two populations of brainstem PS-on GABAergic neurons and a population of hypothalamic PS-on neurons co-expressing GABA and a peptide, melanin concentrating hormone play crucial roles in PS control. These new results might open new avenues for treatments of pathologies such as narcolepsy, REM sleep behaviour disorder and sleep apnea.
Pierre-Herve? LUPPI, CRNL/Sleep