Anisomycin Disrupts a Contextual Memory Following Reactivation in a Cocaine-Induced Locomotor Activity Paradigm

In experiments examining the potential reconsolidation of drug-associated contextual memories, rats were given a single pairing of cocaine with a specific context, and the ability of the protein synthesis inhibitor anisomycin administered following a context-only memory retrieval trial to impair conditioned locomotor sensitization was tested. Rats receiving 150 mg/kg anisomycin immediately following a 5-min reexposure to the cocaine-conditioned context showed decreased activity compared with the vehicle control group in response to a low-dose cocaine challenge during a subsequent test for conditioned sensitization. This effect was not seen when anisomycin was administered following a 30-min reexposure to the context or when anisomycin was administered 25 min after a 5-min reexposure. These results are consistent with a growing literature suggesting that following retrieval, associative contextual memories may undergo a transient protein synthesis-dependent reconsolidation phase that normally serves to maintain memory.