Fear memories require protein synthesis in the amygdala for reconsolidation after retrieval

Abstract

'New' memories are initially labile and sensitive to disruption before being consolidated into stable long-term memories. Much evidence indicates that this consolidation involves the synthesis of new proteins in neurons. The lateral and basal nuclei of the amygdala (LBA) are believed to be a site of memory storage in fear learning. Infusion of the protein synthesis inhibitor anisomycin into the LBA shortly after training prevents consolidation of fear memories. Here we show that consolidated fear memories, when reactivated during retrieval, return to a labile state in which infusion of anisomycin shortly after memory reactivation produces amnesia on later tests, regardless of whether reactivation was performed 1 or 14 days after conditioning. The same treatment with anisomycin, in the absence of memory reactivation, left memory intact. Consistent with a time-limited role for protein synthesis production in consolidation, delay of the infusion until six hours after memory reactivation produced no amnesia. Our data show that consolidated fear memories, when reactivated, return to a labile state that requires de novo protein synthesis for reconsolidation. These findings are not predicted by traditional theories of memory consolidation.

Tetris and Word games lead to fewer intrusive memories when applied several days after analogue trauma

“…The latter method is also in line with human and animal conditioning studies, where a single unreinforced CS is usually used for memory reactivation (e.g. Nader, Schafe, & LeDoux, 2000; Schiller et al, 2010). The intervention is then placed during expectation of upcoming trauma, which fits with the view that ‘warning signals’ are a key component of a trauma memory.…”

Selective Association Between Tetris Game Play and Visuospatial Working Memory: A Preliminary Investigation

“…Interestingly, the memory reconsolidation literature suggests that even established memories become labile again upon reactivation from LTM and need to re‐stabilize and reconsolidate to persist (Nader, 2003; Nader, Schafe, & Le Doux, 2000; Walker et al, 2003). Therefore, the effects of Tetris on intrusive memories could be observed after any length of post‐encoding delay in principle, as long as the memory is labile and thus amenable to interference, for example, as has been tested 24 h or more after encoding (James et al, 2015).…”

Modification of episodic memories by novel learning: a failed replication study

“…Loftus & Palmer, 1974), but, prior to their groundbreaking work on reconsolidation (e.g. Nader, Schafe, & LeDoux, 2000), behavioural neuroscientists believed that emotional memories were indelible (LeDoux, Romanski, & Xagoraris, 1989). A seminal study by Nader et al (2000) brought these two research disciplines closer by demonstrating that consolidated memories can indeed be changed.…”

“…Nader, Schafe, & LeDoux, 2000), behavioural neuroscientists believed that emotional memories were indelible (LeDoux, Romanski, & Xagoraris, 1989). A seminal study by Nader et al (2000) brought these two research disciplines closer by demonstrating that consolidated memories can indeed be changed. Nader et al showed that memories are impaired when the reconsolidation process is disrupted, by injecting rodents with a pharmacological agent (i.e.…”