Fig. 2

PACK-mediated inhibition in vivo is reliable and reversible. A Analysis of responses to 10-ms blue light pulses during the first 50 min of the light ON phase. 2-s long LFP snippets before and after each light pulse were extracted and overlaid with a color-coding from gray to black (first to last LFP snippet). To enable comparison to baseline, 2-s snippets at corresponding time points were extracted from pre-recordings. B, D Representative plots of overlaid LFP snippets from a pre-recording and light ON recording with B 0.05-Hz and D 0.1-Hz illumination. C, E Line lengths (mV/s) were calculated for each 2-s LFP snippet and the mean “pre,” “before pulse,” and “after pulse” line length per mouse is presented. The mean “after pulse” line length was significantly smaller than “pre” and “before pulse” line length in both illumination modes, indicating a reliable reduction of neuronal activity. C Baseline (“pre”) and “before pulse” line lengths were similar in 0.05-Hz sessions, demonstrating recovery from inhibition before the next pulse was applied. E LFP line length was reduced throughout the 0.1-Hz light ON period (in blue), including before and after pulse phases, suggesting the inhibition was stable. RM ANOVA and Tukey’s multiple comparison test (n = 6 mice, average of 2 recordings, gray lines), *p < 0.05, **p < 0.01, ***p < 0.001. Mean presented in black with SEM as error bars