Fig. 5.

Illustration of shift in preferred phase of firing of a hippocampal place cell within the local theta cycle between foraging and avoidance contexts. A) Rate map showing a place cell firing field (left) during a foraging session on the stable arena (right) that preferred to fire in the ascending phase of theta (middle); B) Rate map for the same cell in A that also had a place cell firing field (left) during an active avoidance session on the rotating arena (right) that shifted its tendency to fire to the descending phase of theta (middle); C) Roseplot histogram (left) where the number of action potentials for the cell in A are binned by 20 18° bins (0–360°). The spectrogram for a 5-sec period of recording is shown between the raw (top) and filtered (5–12 Hz) EEG signal. Black lines indicate when these action potentials occur within the ascending phase of the raw and filtered EEG traces; D) Roseplot histogram (left) where the number of action potentials for the cell in B are binned by 20 18° bins (0–360°). The spectrogram for a 6 sec period of recording is shown between the raw (top) and filtered (5–12 Hz) EEG signal. Black lines indicate when these action potentials occur within the descending phase of the raw and filtered EEG traces.