THE INTRINSIC EFFECTS OF SARMAZENIL ON SLEEP PROPENSITY AND PERFORMANCE-LEVEL OF SLEEP-DEPRIVED SUBJECTS

The effect of two dosages of sarmazenil (RO 15-3505) on sleep propensi ty and performance was investigated in a double-blind, placebo-control led paradigm. The design included three 24-h testing periods, separate d by at least one 7-day rest period, commencing after 24-h of sleep de privation. Twelve normal, healthy, adult males (mean age 27 +/- 2.8 ye ars) were paid to participate. During the experimental periods, they c ame to the sleep laboratory at 2100 hours and spent the night awake un der close supervision. At 0700 hours, a schedule of 7 min ''attempting '' sleep in bed, 13 min awake outside the bedroom, began. This schedul e was maintained for 24 h. Repeated administrations of 1 mg and 2 mg s armazenil significantly reduced the 24-h levels of total sleep. This w as particularly evident during the period 0700-2300 hours. Sarmazenil also significantly improved reaction time and tended to increase the n umber of correct responses in the ''categories search'' task. Sarmazen il tended to improve reaction time in the ''Stroop'' test but this was significant only for the ''easy'' version of the test during the nigh t.