A role for the prefrontal cortex in recall of recent and remote memories

Declarative memories are thought to be initially stored in the hippocampus, and then transferred to the neocortex. This is a key feature of the standard model of consolidation and is supported by studies reporting a requirement for activity within the neocortex for recall of remote, but not recent, hippocampal-dependent memories. New evidence from our and other laboratories, however, suggests that, for trace fear conditioning, memories are stored in the rodent medial prefrontal cortex and in the hippocampus from the time of training. Consistent with this, we show that activity in the medial prefrontal cortex is necessary for retrieval of recent and remote memories, suggesting that information stored in this neocortical structure from the time of training is necessary for memory recall.