REM sleep deprivation decreases apomorphine-induced stimulation of locomotor activity but not stereotyped behavior in mice.

1. Effects of rapid eye movement (REM) sleep deprivation on central dopaminergic system were investigated by testing the behavioral responses to apomorphine and brain dopamine metabolism in mice. 2. REM sleep deprivation for 48 hr significantly suppressed apomorphine.HCl (3.0 and 6.0 mg/kg, i.p.)-stimulated spontaneous locomotor activity without affecting the intensity of stereotyped behavior. 3. Neither the latency of nociceptive response in a hot-plate test nor the duration of pentobarbital-induced sleep was changed by REM sleep deprivation. 4. Dopamine turnover in the striatum and the nucleus accumbens of REM sleep-deprived mice was significantly higher than that of control animals. 5. These results suggest that REM sleep deprivation may decrease the function of postsynaptic dopamine receptor in the mesolimbic but not nigrostriatal dopaminergic system.