Fig. 4

Light activation of bPAC reversibly increases neuronal activity in CA1. A Experimental design. We targeted bPAC-mCherry to excitatory neurons in the CA1 area using the AAV9 vector. B Implantation, C recordings, and D histological analysis were performed like in PACK mice. Scale bar: 200 μm. E Representative snippets of a 0.1-Hz recording show persistently increased LFP magnitude during the light ON phase in bPAC-expressing CA1. F In the light ON phase, the mean line length was significantly increased compared to the baseline (pre) level. In the post-recordings, the line length was reduced compared to the baseline. One-sample t-test (n = 6, average of two recordings, gray lines), **p < 0.01. G The spectrograms, taken from the same time window as LFP snippets, demonstrate elevated spectral power. H The mean PSD during 0.1-Hz illumination was increased at frequencies above ~ 10 Hz. I Theta (4–12 Hz), beta (12–30 Hz), and gamma (30–120 Hz) powers are slightly but not significantly elevated during the light ON phase. Two-way RM ANOVA, Dunnett’s multiple comparison test, **p < 0.05. Mean presented in black with SEM as error bars