Hippocampal place cells and the generation of a temporal code

Pyramidal cells in the hippocampus of freely moving rats have a spatially specific activity pattern which provides information to downstream in the phase of cell activity. We present a minimal biophysical model for the generation of the phase information from a combination of two inputs: a short duration spatial trigger and the animal's running speed. This single input is shown to determine the start and end of the spatial firing, and a transient phase code for location. Three different simple networks are shown to produce this behavior, without changes in synaptic conductance or connectivity.