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.