Figure 1.

Place cells are characterised by their stable spatial firing fields.

(A) Standard configuration for place cell recording. A rodent with chronically implanted extracellular electrodes forages in an open enclosure. Upper right: the animal’s path over the course of a 10-minute trial is indicated by the black line, action potentials from a single place cell are superimposed in red. Lower right: firing rate-map of the raw data indicating the mean firing rate of the cell per spatial bin. ‘Hotter’ colours indicate higher rates, peaking at 8.3 Hz (shown above the map); dark blue indicates low rates (0–20% of the peak rate); white bins are unvisited locations. (B) On exposure to an unfamiliar enclosure place cells ‘remap’, rapidly generating a novel representation; individual cells change their firing rate and field locations relative to each other and the environment ^{32, 64, 158}. Recordings of four CA1 place cells (columns) made in similarly sized (70 cm square) enclosures located in different rooms (rows). Remapping is evident as a change in firing correlates and rates.