Hippocampal place cells: the "where" of episodic memory?

Neuropsychologists have clearly implicated the hippocampus in the consolidation of memory, particularly episodic memory, the mental replay of past experiences. When recorded from behaving animals, by far the most obvious firing pattern of the primary neurons of the hippocampus is the place field: a cell tends to fire only when the animal's head is in a particular part of its environment. It seems reasonable to suspect that the primary firing correlate of the primary neurons of a structure should underlie the primary function of that structure as revealed by behavioral lesion experiments. However, we are currently still at a loss to explain how the firing of hippocampal neurons contributes to hippocampal function. This review seeks to examine the commonalities between place cells and episodic memory, and posits that an analogy can be made between the stabilization of place fields and the consolidation of memory. Copyright (c) 2006 Wiley-Liss, Inc.