Extended Data Figure 7: Phase specificity of the close loop stimulation technique. | Nature

Extended Data Figure 7: Phase specificity of the close loop stimulation technique.

From: Prefrontal neuronal assemblies temporally control fear behaviour

Extended Data Figure 7

a, Representative distribution of stimulation pulses in relation to the phase of the 4 Hz oscillation (black line, filtered LFP 3–6 Hz) when the stimulation was applied in the ascending phase of the oscillation (bins of 18°). b, Representative cross-correlogram between two dmPFC PNs (neurons A and B) participating to neuronal assemblies during (blue bars), or outside (grey bars) optogenetic inhibition of PV interneurons. Note the reduction in joint firing activity when the stimulation was on. Reference events correspond to the spikes of the neuron A (dashed line at time 0, bins of 5 ms). c, Firing frequency of dmPFC neurons A (top) and B (bottom) without optogenetic stimulation (grey bars, bins of 15 ms) or when the pulse was applied in the ascending phase of the 4 Hz oscillation (blue bars, bins of 15 ms) (black line, filtered LFP 3–6 Hz). d, Corresponding joint peri-stimulus time histograms performed between the same dmPFC neurons A and B when the pulse was applied in the ascending phase of the 4 Hz oscillation (top) or without stimulation (bottom). Note the inhibition of the co-firing activity when the stimulation was on. e, Firing probability per degree of identified PV+ interneurons as a function of 4 Hz oscillations phase (n = 14 PV+ interneurons). f, Cumulative firing probability per degree for individual PV+ interneurons (open circles) during the ascending or descending phase of 4 Hz oscillations and corresponding averaged cumulative firing probability (black bars, n = 14 PV+ interneurons, Wilcoxon signed rank test, P = 0.733). g, i, Top: firing of a PV+ interneuron in a mouse expressing ChR2 or ArchT in PV+ interneurons in the dmPFC in response to blue or yellow light (light-pulse duration 30 ms; 150 trials). Bottom: mean peri-stimulus time histograms of all PV+ interneurons displaying significant light-evoked excitation or inhibition (n = 10 PV+ from five mice infected with ChR2; n = 4 PV+ from two mice infected with ArchT, light-pulse duration, 30 ms). Bins of 5 ms. h, j, Top: firing of a PN in a mouse expressing ChR2 or ArchT in PV+ interneurons in the dmPFC in response to blue or yellow light activation of PV+ interneurons (light-pulse duration, 30 ms; 150 trials). Bottom: mean peri-stimulus time histograms of all PNs displaying significant light-evoked inhibition or excitation (n = 160 PNs from seven mice infected with ChR2; n = 117 PNs from five mice infected with ArchT; light-pulse duration, 30 ms). Bins of 5 ms. Error bars, mean ± s.e.m.

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