Behavioural profiles after morphine withdrawal precipitated by naloxone (nx) in animals chronically administered with vehicle (tween80) or CP-154,526 (CP).

*p**p2 test). Animals received subcutaneous implantation of morphine (75 mg) pellets. On day 6 rats were injected with vehicle or CP-154,526 (20 or 30 mg/kg, i.p.) 30 min before naloxone (1 mg/kg, s.c.) and were decapitated 60 min after the opioid antagonist administration. The behaviours are shown as the number of animals exhibiting the withdrawal signs of the total number of animals observed for 60 min.