Updating memories: Changing the involvement of the prelimbic cortex in the expression of an infant fear memory

► We examine the changing role of the PL in fear expression across development. ► Rats trained as infants but tested as juveniles do not use the PL to express fear. ► The role of the PL in fear expression depends on the age of the animal at training. ► Fear expression becomes PL-dependent when a second training experience is given. ► Later learning experiences aid in the recovery and updating of infant memories.