Figure 6.

Action Potentials in GCs Are Phase Locked to the Local LFP in Both Theta and Gamma Frequency Bands

(A) Simultaneous recording of LFP and WC membrane potential in awake condition. Top: minimally filtered trace (150 Hz low-pass; green); middle (red): same trace filtered in the theta (second trace from top) and gamma range (third trace from top); bottom: WC membrane potential (black).

(B) Power spectrum of the LFP in the three experiments in which GCs generated action potentials in awake condition (see Figure 2E). Green curves, single experiments; Black curve, average.

(C) Coherence between LFP and WC membrane potential recording (including action potentials). Blue, original data; brown, shuffled data. Shaded areas indicate SEM. Control data were significantly different from shuffled data (p < 0.05). Note the presence of coherence peaks in both theta and gamma frequency band.

(D) Summary bar graph of maximum coherence.

(E) Summary bar graph of corresponding frequency in theta (left) and gamma (right) frequency range.

(F and G) Phase relationship between action potential/burst onset and theta cycle (F) or gamma cycle (G) in one of the three firing GCs in awake condition.

(H) Angular lag between action potential/burst onset and LFP trough in awake rats for theta and gamma frequency oscillations. Note that GCs fired in the descending phases of theta and gamma cycles, respectively. See also Figures S4 and S7.