Extended Data Fig. 9: Optogenetic activation of the FNE-IO neurons drives saccade.
From: Excitatory nucleo-olivary pathway shapes cerebellar outputs for motor control
Related to (Fig. 6a-d). a, Polarhistogram of the saccade movement directions following 250-ms photoactivation (50 Hz, 50% duty cycle, 3.00 mW). Unilateral activation of FNE-IO neurons drives nasal saccade of ipsilateral eye. Number of trials in each bin is normalized to the total saccade trials (n = 207 from 9 mice), bin size = 6.4°. b, Histogram of the peak velocities of all evoked saccades. c, Trial-by-trial correlation between the saccade amplitude and velocity. Left: heatmaps showing saccade amplitudes (upper) and velocities (lower) of a representative mouse. Each row represents one trial, and all trials are sorted based on the peak velocities. The dashed line indicates photoactivation onset. Right: scatter plot of all saccade trials (circles) and the curve fitting (linear regression model, P = 3.5×10−10) from the same mouse (see R2 value in the panel). d, Group summary from 9 mice indicating consistent trial-by-trial correlations between evoked saccade velocity and amplitude. e, Representative eye movement traces following 250-ms photoactivation with graded intensities in an example mouse. Orange traces are identified as photo-evoked saccades (see Methods); gray traces are unresponsive trials; black traces indicate the average saccadic movement of each condition (mean ± s.e.m.). Post-saccadic drift (PSD in the blue shaded-line rectangle) is defined as the movement deviation from the saccade peak to the position at 50 ms after the peak. The probabilities of evoked saccades increase as a function of photoactivation intensities (see summary for all mice in Fig. 6d). f, Summary of the saccade onset, PSD, amplitude, and velocity for different photoactivation intensities. One-way ANOVA with Tukey’s multiple comparisons, n = 9 mice, P = 0.18, 0.06, 0.22, and 0.37 for each comparison. Dots and bars represent mean ± s.e.m. g, h, Same as (e, f), but for eye movements following different photoactivation durations. Yellow traces are identified as photo-evoked saccades; gray traces are unresponsive trials; black traces are the average saccade movements (mean ± s.e.m.). h, The probability of evoked saccade following 10-ms photoactivation was minimal compared to the other conditions (one-way ANOVA with Tukey’s multiple comparisons, n = 9 mice, P = 1.72×10−6). There was no significant difference in saccade probabilities among the 50-ms, 250-ms, and 500-ms photoactivations (P = 0.51). The kinematics of evoked saccades are dependent on the photoactivation duration. Photoactivation of 50 ms evokes distinct saccadic movements which rapidly return to the initial eye position, resulting in larger PSDs but comparable onsets, amplitudes, and velocities to those driven by 250-ms and 500-ms photoactivations (P = 0.0041, 0.078, 0.32, and 0.26 for each comparison). Dots and bars represent mean ± s.e.m.
