The role of protein synthesis in memory reconsolidation in different time periods after fear conditioning in mice

We have studied the role of protein synthesis in reconsolidation of memory, activated by reminder at different time period after initial acquisition. Mice were trained in a single-trial fear conditioning task and then subjected to reminder, preceded by injection of protein synthesis inhibitor cycloheximide. It was found that this procedure impaired later memory retrieval if applied at 3, 6 and 24 h as well as 14 and 30 days after initial training. This data suggests that reactivated memory is followed by protein synthesis-dependent reconsolidation both at short (3-6 h) and long (14-30 days) intervals after initial acquisition.