THE EFFECTS OF ANANDAMIDE ON MEMORY CONSOLIDATION IN MICE INVOLVE BOTH D-1 AND D-2 DOPAMINE-RECEPTORS

Post-training administration of anandamide (1.5, 3, 6 mg/kg) dose-depe ndently impairs the retention of an inhibitory avoidance response in m ice. The effects on retention performance induced by the drug appear t o be due to an effect on memory consolidation, as they were observed w hen drugs were given at short, but not long, periods of time after tra ining, i.e. when the memory trace was susceptible to modulation. Pretr eatment with either selective D-1 or D-2 dopamine (DA) receptor agonis ts, SKF 38393 and quinpirole, at doses that were ineffective when give n alone (5 and 0.25 mg/kg, respectively), antagonized the effects of a nandamide on memory consolidation, suggesting that D-1 and D-2 recepto rs are similarly involved in the effects of anandamide on memory conso lidation. These results are discussed in terms of a possible inverse r elationship between the modulation of memory processes by endogenous c annabinoid and DA systems.