Furthermore, the blockade of the CeA cannabinoid CB1 receptors by the injection of AM251 (0.75 and 1ng/rat) reversed the potentiative effect of nicotine (0.6mg/kg, s.c.) on morphine-induced amnesia.
Moreover, the injection of a cannabinoid CB1 receptor agonist, ACPA, or a selective CB1 receptor antagonist, AM-251, into the mPFC prior to testing had no effect on memory retrieval by itself and also on morphine-induced memory loss.