Disruption of memory reconsolidation impairs storage of other, non-reactivated memory

► Intra-BLA lidocaine infusion following the reactivation of cocaine-induced CPP diminished later CPP magnitude. ► Intra-BLA lidocaine infusion following the reactivation of passive avoidance (PA) diminished subsequent PA expression. ► Intra-BLA lidocaine infusion following PA retrieval diminished both PA and cocaine-induced CPP performance in retests. ► Intra-BLA lidocaine infusion following CPP retrieval diminished subsequent CPP and PA performance in retests. ► Retrieval of two memories activated greater number of neurons than those activated by one memory retrieval in BLA. Two hypotheses were tested in this study. First, blockade of neural activity by lidocaine immediately following the retrieval of a memory may impair the reconsolidation and subsequent expression of that memory. Second, a non-retrieved memory would not be affected by this lidocaine treatment. Since the basolateral nucleus of the amygdala (BLA) is involved in emotion-related memory, an intra-BLA lidocaine infusion was used immediately after the retrieval of two emotion-related memories, the step-through passive avoidance response (PA) and cocaine-induced conditioned place preference (CPP). Intra-BLA lidocaine infusion immediately after cocaine-induced CPP retrieval diminished CPP magnitude in retests. However, intra-BLA lidocaine infusion alone did not affect cocaine-induced CPP performance. Intra-BLA lidocaine infusion immediately after PA retrieval decreased PA performance in retests. Omission of PA retrieval procedure, intra-BLA lidocaine infusion did not affect subsequent PA performance. Surprisingly, intra-BLA lidocaine infusion immediately following the retrieval of PA or cocaine-induced CPP diminished both PA and cocaine-induced CPP performance in the retests. Finally, Fos-staining results revealed that a number of BLA neurons were activated by the retrieval of both cocaine-induced CPP and PA. We conclude that inactivation of neural activity in BLA immediately following retrieval of a fear or cocaine-conditioned memory can impair subsequent expression of both memories. More importantly, retrieval of a memory does not seem to be an absolute condition for rapidly changing the memory.