EFFECTS OF THE SELECTIVE 5-HT1B AGONIST, CGS-12066B, ON SLEEP-WAKING STAGES AND EEG POWER SPECTRUM IN RATS

Sleep/waking stages and EEG power spectra were studied in rats for 8 h following intraperitoneal administration of CGS 12066B, a selective 5 -HT1B agonist. Waking was increased and rapid eye movement (REM) sleep decreased in a dose-dependent manner. Total slow-wave sleep (TSWS) wa s reduced, but only in the first 2 h period. The latencies to REM slee p and stable sleep were increased dose-dependently. The drug also indu ced profound behavioural changes that may account for some of the slee p/waking changes. EEG power densities in waking and TSWS were reduced dose-dependently from 7 to 20 Hz after CGS 12066B, suggesting a tenden cy towards general deactivation. The increase in waking together with a general deactivation suggest complex effects of CGS 12066B on the sl eep/waking axis.