The roles of RNA synthesis and protein translation during reconsolidation of passive-avoidance learning in the day-old chick.

This series of experiments investigated the role of protein translation and RNA synthesis on consolidation and reconsolidation of passive avoidance learning (PAL) in day-old chicks. Although it is well established that protein translation is required after a reminder, there are conflicting reports in the literature concerning the requirement for RNA synthesis at this time. Day-old male New HampshirexWhite Leghorn chicks were trained on a single trial passive avoidance task. The results confirmed the requirement for protein translation during reconsolidation with memory deficits induced by anisomycin (ANI) (10mg/kg) detected at 60min post-reminder. It was also established that RNA synthesis was required for consolidation of PAL through inhibition by 5,6-Dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) (0.075microg/kg), administered at or after training. The same dose of DRB was also found to inhibit memory post-reactivation. However injections were required before the reminder trial and memory deficits were evident by 60min, consistent with that found for ANI post-reminder. As with ANI, the DRB-induced memory deficit post-reminder was also transient, and resolved by 24h post-reminder. For both reconsolidation drug studies, the memory deficit was wholly dependent on the memory being reactivated by a reminder-trial. The study highlights an important role for RNA synthesis following memory reactivation.