Figure 2.

Motor Cortex Inhibition Delays Visually Guided Corrective Turns

(A) Mice spontaneously turn left and right as they learn to traverse the virtual corridor. The amplitude of spontaneous turns increased over the course of training (days 1 to 8) for both left (blue) and right (red) turns. Shading indicates SEM over turns. Turns per day, left: 184 ± 27; right: 186 ± 28 (mean ± SD, n = 22 mice).

(B) Average acceleration during spontaneous turns increased with training (p < 10⁻⁸, R² = 0.19, n = 22 mice; linear trend analysis; see STAR Methods). Error bars indicate SEM over mice (n = 22 mice).

(C) Speed profiles of the spontaneous turns without inhibition of motor cortex (left panel, n = 14 mice) and the spontaneous turns initiated during inhibition of motor cortex (right panel, n = 14 mice, data from the same mice as in left panel), executed on performance testing days in expert mice, sorted by maximum speed. Motor cortex inhibition did not prevent mice from executing spontaneous turns. Color indicates turning speed.

(D) Average speed profile of turns without (black) and with (blue) bilateral inhibition of motor cortex. Same data as shown in (C). Shading indicates SEM over mice (n = 14 mice). Note that turning speed with or without motor cortex inhibition was not different in a window 3 s after turn onset (marked by dashed lines). n.s., not significant; Wilcoxon rank sum test.

(E) Average speed profiles during corrective turns to the left (blue) and right (red) induced by visual offset perturbations over the course of training (days 3 to 8, the first 2 days did not have visual offset perturbations, left turns: n = 632, 666, 688, 803, 776, 884; right turns: 675, 687, 725, 806, 749, 907 in 22 mice, respectively). Shading indicates SEM over turns. Turns per day, left: 34 ± 4; right: 34 ± 4 (mean ± SD).

(F) Acceleration during corrective turns induced by visual offset perturbations increased over the course of training (p < 10⁻⁵, R² = 0.15, n = 22 mice; linear trend analysis; see STAR Methods). Error bars indicate SEM over mice (n = 22 mice).

(G) Speed profile of 321 visual offset perturbation-induced corrective turns in expert mice that had reached plateau performance without (left panel, n = 14 mice, data from same mice as in C) and with (right panel, 353 trials, n = 14 mice, data from the same mice as in left panel) inhibition of motor cortex concurrent with visual offset perturbation for 3 s (blue bar). Turns are sorted by latency to peak velocity. In a subset of trials (55% ± 5%, mean ± SEM, see STAR Methods), mice delayed their corrective turn response until after motor cortex inhibition ceased. Color indicates turning speed.

(H) Average speed profile of visual offset perturbation-induced corrective turns without (black) and with (blue) bilateral inhibition of motor cortex for 3 s starting concurrently with the visual offset perturbation (time 0). Same data as shown in (G). Shading indicates SEM over mice (n = 14 mice). Turning speed was lower with motor cortex inhibition (0 s – 3 s after perturbation onset). ^∗∗p < 0.01; Wilcoxon rank sum test.