Figure 6.

Rhythmic modulation of anteroventral units corresponds to the activity of theta cells. A, Three examples of cross-correlograms between theta and HD-by-theta units recorded from the same tetrode channel. Time 0 is denoted by the dashed white line. B, Cross-correlogram between theta and HD units recorded from the same tetrode channel. C, Sample recordings, representing the parallel activity of theta (red) and HD-by-theta (purple) units. The left panels represent the recorded activity (from 3 different cells) in one animal, while the right panels show similar episodes (from 3 different cells) in a second animal. Simultaneously recorded LFP (green trace) is below. The rectangular box denotes parallel theta cell activity, HD-by-theta pause, and LFP oscillation trough. Bottom, Concurrent head direction (black trace) measured in degrees (y-axis).