Extended Data Figure 9: Phase-specific optogenetic disinhibition of dmPFC PNs enhanced fear behaviour.

a, Timeline scheme for the optogenetic stimulation protocol on day 3 with stimulation targeting the descending phase of 4 Hz oscillation cycle (top) and day 4 with stimulation targeting the ascending phase of 4 Hz oscillation cycle (bottom). b, d, Comparison of freezing levels between CS⁺ 1 and CS⁺ 2–4 for epochs 10 s preceding, during and 30 s after CS⁺ during optogenetic stimulation of PV-IRES-Cre mice infected within the dmPFC with ArchT (pre-CS⁺, CS⁺ and post-CS⁺ respectively) on day 3 (b) and day 4 (d). On day 3, descending phase stimulation after CS⁺ 1 had no effect on freezing levels during subsequent CS⁺ epochs before, during or after CS⁺ (n = 5 ArchT mice, repeated-measures two-way ANOVA, factor 1: CS⁺ 1 versus CS⁺ 2–4, P > 0.05; factor 2: epoch, P < 0.05; F₁ × F₂, P > 0.05; Student–Newman–Keuls post-hoc test within factor 1, **P < 0.01 compared with both pre- and post-CS⁺ epochs, *P < 0.05 comparing pre-CS⁺ with CS⁺ epochs). On day 4, ascending phase stimulation after CS⁺ 1 had no effect on freezing levels during subsequent CS⁺ epochs before, during or after CS⁺ (n = 5 ArchT mice, repeated-measures two-way ANOVA, factor 1: CS⁺ 1 versus CS⁺ 2–4, P > 0.05; factor 2: epoch, P < 0.05; F₁ × F₂, P < 0.05; Student–Newman–Keuls post-hoc test within factor 1, ***P < 0.001 compared with both CS⁺ and post-CS⁺ epochs, *P < 0.05 comparing pre-CS⁺ with CS⁺ epochs). c, e, Left: time-resolved changes in freezing behaviour during light-mediated inhibition of dmPFC neuronal assemblies in the descending (c) or ascending (e) phase of the 4 Hz oscillation in PV-IRES-Cre mice infected within the dmPFC with ArchT (descending phase: first CS⁺, n = 5; ascending phase: first CS⁺, n = 5) or GFP (descending phase: first CS⁺, n = 7; ascending phase: first CS⁺, n = 4; descending phase: two-way ANOVA, factor 1: ArchT versus GFP, P > 0.05; factor 2: time, P > 0.05; F₁ × F₂, P > 0.05; ascending phase: two-way ANOVA, factor 1: ArchT versus GFP, P < 0.01; factor 2: time, P < 0.01; F₁ × F₂, P < 0.01). Shaded area represents the period during which the light stimulation was applied. Right: averaged freezing behaviour during the stimulation in the descending (c) (ArchT n = 5; GFP n = 7, Mann–Whitney test, ArchT versus GFP, P > 0.05) or ascending phase (e) (ArchT n = 5; GFP n = 4, Mann–Whitney test, ArchT versus GFP, *P < 0.05). Error bars, mean ± s.e.m.