Pursuing reconsolidation in ethanol-CPP: memory reactivation in different conditions did not trigger destabilization

Abstract

Consolidated memories can return to a labile state during retrieval, through destabilization, and must be reconsolidated to persist. Associative memories of contextual cues paired with hedonic effects of drugs of abuse exert a pivotal role in maintaining maladaptive behaviors in addiction. Thus, impairment of reconsolidation of drug-associated memories may provide a potential strategy to reduce drug-seeking and relapse in addiction. It is critical to understand the conditions under which a consolidated memory becomes labile and may undergo reconsolidation. After inducing ethanol Conditioned Place Preference (CPP; 2 g/kg ethanol, i.p.) in male mice, we examined different parameters during the reactivation session that could turn memory susceptible to disruption by systemic injection of the protein synthesis inhibitor cycloheximide (CHX, 100 mg/kg, i.p.). Reactivation with free access to the apparatus (similarly to a Test session, for 10, 5, or 3 min) or Reactivation sessions restricted to ethanol-paired compartment with no ethanol (for 10 or 5 min), or with the administration of a low dose of ethanol (5 min session), failed to reduced ethanol-preference after CHX administration. These findings suggest that boundary conditions constraint memory in ethanol-CPP to undergo reconsolidation.