Fig. 3

RIS photoactivation suppressed motor neuron (MN) synchrony and Ca²⁺ oscillations. a Exemplary voltage clamp recording of BWM cell, postsynaptic to MNs. Blue bar denotes RIS::ChR2 photostimulation b, c Analysis (mean ± SEM) of mPSC frequency (b) and amplitude (c). Blue bar: Illumination period; n = 11 animals. d Fourier transform with multi-taper analysis of mPSC events across the observed frequencies. Mean (solid lines) ± SEM (dashed lines) of the periods before, during, and after RIS photostimulation of n = 11 animals. e RCaMP fluorescence in cholinergic neurons in the head with region of interest from dorsal nerve ring (NR; d and v denote dorsal and ventral portions in f) through ventral to retrovesicular ganglia (VG, RVG) marked in white; black: pharynx outline. Scale bar = 25 µm. For identity of cells imaged, see Supplementary Fig. 3A. f Kymograph representation of cholinergic neuron Ca²⁺ dynamics from the dorsal NR to posterior RVG. Scale bars, upper = 20 s, lower = 10 s; blue bar: illumination period, lower three panels show expanded views. g Autocorrelation analysis (as in Fig. 2e); distribution of mean change in Ca²⁺ oscillation period in cholinergic neurons, per animal, relative to before RIS photoactivation. When no oscillations occurred, the duration of photostimulation (60 s) was assumed as minimal period. Number of animals indicated in gray. ***p ≤ 0.001; **p ≤ 0.01; *p ≤ 0.05; statistical significance tested by two-way ANOVA in d and ANOVA, Bartlett’s test, and Bonferroni’s multiple comparison test in g