Fig. 7: Fear conditioning with optogenetic manipulation and 4-Hz photostimulation.

a Plots showing the frequency of whole-body plethysmographic signals during the prestimulation (2 s), 4-Hz photostimulation (162.5-ms pulse-on and 87.5-ms pulse-off, duty cycle: 65.0%; 16 times for 4 s), flat photostimulation (2 s), and poststimulation (2 s) periods in awake Cre⁻ and Cre⁺ mice. b Plots showing the frequency of whole-body plethysmographic signals during the prestimulation (2 s), photostimulation (flat, 2 s), and poststimulation (2 s) periods in awake Cre⁺ mice (χ²(2) = 16.91, P = 0.0002, Friedman test; photostimulation: P = 0.003 compared to prestimulation, P = 0.003 compared to poststimulation, post hoc pairwise Wilcoxon signed-rank test with two-sided and Bonferroni correction). c Plots showing the frequency during the prestimulation (2 s), 4-Hz photostimulation (4 s), and poststimulation (2 s) periods in Cre⁻ (blue) and Cre⁺ (orange) mice. d Plots showing the variability in the cycle duration in Cre⁻ and Cre⁺ mice. e Plots showing changes in the pressure amplitude in Cre⁺ mice. f, g Plots showing active time between CS⁻ and CS⁺ during the offset time blocks (light orange zone) and onset time blocks (light green zone) in Cre⁻ (blue) and Cre⁺ (orange) mice. The scale bar is 2 s in (a). Cre⁻ mice (n = 9, 4 females and 5 males, blue) and Cre⁺ mice (n = 11, 7 females and 4 males, orange) in (b–e, g). ^†P < 0.05, ^††P ≤ 0.01, ^†††P < 0.005 (main effects and interactions using ANOVA, Friedman test, and post hoc pairwise comparisons), *P < 0.05, **P ≤ 0.01, ***P < 0.005 (two-tailed Welch’s t test and two-tailed paired t test), ⁰P < 0.05 (two-tailed one-sample t test against zero). Box plots indicate median, first, and third quantiles, and minimum and maximum values. Bar and line plots indicate means ± SEM. Circles in the graph represent individuals.