Figure 4.

Example of a place cell with fields on both the small (left column) and the large (right column) tracks coupled with a local interneuron. The first three rows present plots of phase, position, and firing rate activity (see Fig. 1) for the principal cell, and the next three rows present the same information for the putative monosynaptically coupled interneuron. Running direction is indicated by the arrow on the top of the figure. The bottom row shows the cross-correlograms for each neuron pair. The rate of precession of the pyramidal cell on the small track was 0.022 cm/°, whereas the interneuron precessed at a rate of 0.034 cm/° on the small track. On the large track, the pyramidal cell and interneuron precessed at rates of 0.094 and 0.085 cm/°, respectively. This pyramidal cell interneuron pair was recorded from the middle hippocampus of rat 8042.