Summary: Wiltgen et al. 2010

The hippocampus is important for the temporary formation and retrieval of episodic and contextual memories. Damage to this area produces amnesia for new memories. Wiltgen et al. (2010) examined the relationship between memory quality and hippocampus dependency, hypothesizing that memory quality may be critical for determining whether the hippocampus is essential for memory retrieval. Using immediate early gene expression (as measured by RT-PCR), they monitored hippocampal activity in mice during memory retrieval and found that detailed memories require the hippocampus, whereas memories that lose precision do not. The dorsal hippocampus is preferentially activated by retrieval of detailed contextual fear memories and is necessary for the retrieval of detailed memories using a context-generalization procedure. Wiltgen et al. (2010) suggest that detailed contextual memories require the hippocampus, providing a new framework for understanding memory consolidation. Their data help to establish the precise role of the hippocampus in memory retrieval.