Effects of β-adrenergic receptor blockade on drug-related memory reconsolidation in abstinent heroin addicts

Rationale and objective: The reactivation of a consolidated memory can return it to a labile state, a process referred to as reconsolidation. A previous study showed that oral administration of the beta-adrenergic receptor antagonist propranolol before memory reactivation in humans erased the behavioral expression of the fear memory 24 h later. In this study, we investigated whether propranolol impairs the drug-related memory by disrupting the reconsolidation process in heroin addicts. Methods: Seventy abstinent heroin addicts learned a word list (including 10 heroin-related positive words, 10 heroin-related negative words, and 10 neutral words) on day 1. Participants orally administered the beta-adrenergic receptor antagonist propranolol or placebo before retrieval of the word list on day 2. Free recall of the word list and other psychological and physical responses were assessed on day 3. Results: Oral administration of propranolol before reactivation of the word list impaired reconsolidation of drug-related positive and negative but not neutral words in abstinent heroin addicts, and these impairments critically depended on reactivation of the word list. Conclusions: This study extends earlier reports that a p-adrenergic receptor antagonist affects the drug-related memory reconsolidation process. Our findings may have important implications for the understanding and treatment of persistent and abnormal drug-related memories in abstinent heroin addicts. (C) 2011 Elsevier Ireland Ltd. All rights reserved.