THE EXPRESSION OF M1-M3 MUSCARINIC RECEPTOR MESSENGER-RNAS IN RAT-BRAIN FOLLOWING REM-SLEEP DEPRIVATION

WE used in situ hybridization histochemistry to study the effects of R EM sleep deprivation on m1-m3 muscarinic receptor mRNA expression in t he rat brain. REM sleep deprivation for 72h did not affect mi receptor mRNA expression. However, we found significantly increased m3 recepto r mRNA expression in the pontine nuclei and nucleus accumbens-bed nucl eus of the stria terminalis region of REM sleep-deprived rats compared with controls. Paradoxically, we found significantly decreased m2 rec eptor mRNA expression in the pontine nuclei of REM sleep-derived rats us controls. The present findings implicate these structures in the ch olinergic effector pathways of REM sleep, although the type and magnit ude of the effects of these structures on REM sleep may vary with diff erent receptor subtypes.