Extended Data Fig. 4: Membrane potential and firing synchronization around γ events.

a: Intrinsic properties and laminar distribution of neurons recorded using in vivo whole-cell and cell-attached patch-clamp recordings. From left to right: mean membrane potential (Vm), Vm standard deviation (VmSD), firing rate, action potential amplitude, half-width and peak to trough time plotted against recording depth. Neurons between 70 and 315 µm were assigned to layers 2-3 (orange, 8 whole-cell, 2 cell-attached), those between 315 and 455 µm to layer 4 (green, 11 whole-cell, 1 cell-attached) and those between 455 and 735 µm to layer 5 (blue, 6 whole-cell, 2 cell-attached). Cell attached recordings were only used to quantify firing rate. Two cells in layer 2-3 did not fire more than one action potential and were only used to quantify Vm activity. b: Example recording of a layer 2-3 neuron with γ events during transition from quiescence to locomotion (purple). c and d: Average membrane potential of layer 2-3 neurons around γ events (orange) and around randomly selected time points (gray) (n = 8 whole-cell recordings). e: Vm power spectrum of layer 2-3 neurons during (orange) or outside (gray) γ events. Gamma events coincide with an increase of the Vm power distributed across frequencies (n = 8 whole-cell recordings). f: Vm-LFP coherence spectra for layer 2-3 neurons during (orange) and outside (gray) γ event cycles. showing Coherence increase in the γ range during γ events (n = 8 whole-cell recordings). g: Spike-LFP synchrony spectra for layers 2-3 neurons during (orange) and outside (gray) γ event cycles. Spike-LFP synchrony is quantified using the Pairwise Phase Consistency and increases during γ event cycles (n = 11 whole-cell/cell-attached recordings). h, i, j, k, and l: Same as b, c, d, e, and f for layer 4 (n = 11 whole-cell recordings). m: Same as g for layer 4 (n = 12 whole-cell/cell-attached recordings). n, o, p, q and r: Same as b, c, d, e, and f for layer 5 (n = 6 whole-cell recordings). s: Same as g for layer 5 (n = 8 whole-cell/cell-attached recordings). t: Mean of γ events as a function of Vm and average linear fit (dotted line) across recording (n = 25 whole-cell recordings). Vm and γ events rate are correlated. u: Same as g for neurons pooled across layers 2-3, 4 and 5 (n = 30 whole-cell/cell-attached recordings). v: Overall spike-LFP synchrony in the 20–45 Hz range, during (orange) and outside (gray) γ event cycles for whole-cell and cell attached recordings in layers 2-3, 4 and 5. Synchrony is enhanced during γ events and is strongest in Layer 2-3 and Layer 4 neurons. Error Bars: s.e.m; shaded areas: mean ± s.e.m; ***: p ≤ 0.001. See Supplementary Table 1 for detailed statistics and Supplementary Table 2 for statistical samples.