A Pilot Study into the Effects of the CB1 Cannabinoid Receptor Agonist WIN55,212-2 or the Antagonist/Inverse Agonist AM251 on Sleep in Rats
Figure 1
Total time and average length of wakefulness (a, d); NREM (b, e) and REM (c, f) episodes following systemic injections (i.p.) of vehicle (control), WIN-2 (1 mg/kg), AM251 (2 mg/kg), WIN-2 (1 mg/kg) + AM251 (2 mg/kg). WIN-2 significantly increased the time spent in NREM sleep whilst decreasing wakefulness; this was not reversed by AM251. Coadministration of WIN-2 and AM251 reduced the latency to the 1st NREM event (g) whilst AM251 either alone or in combination with WIN-2 increased the latency to the 1st REM (h) episode in comparison to controls. The overall sleep composition (% of NREM versus REM) following each respective treatment is depicted in (i). All data (mean ± SEM) were pooled over a 6 h recording period in the light phase. *; ** for paired comparison relative to vehicle treatment.
