Extended Data Fig. 9: Detailed analysis of low dimensional projection of lSC activity.
From: Striatal indirect pathway mediates exploration via collicular competition
a. Activity projections onto PCs, and different coding directions. Left (blue) and right (red) trials are shown relative to tone onset. Coding direction was defined during −100~0ms window relative to tone onset (left, CD1), 0~100ms relative to tone (center, CD2) and 100~0ms relative to first lick (right, CD3) (see Methods). CD1 was used as a control. b. PCA on the original data (without first calculating and removing CD2 information as in Figure 5). Left/right lick (i.e. choice) information is found in PC2 (2nd column). c. Left-right choice selectivity measured from the projection of the neural activity along the indicated axes. Selectivity measures how separable the trajectories are along the selected axis. The given P-values are for comparison by one sample two tailed t-test (P***<0.0005, P*<0.05). The trajectories are well-separable along different choice axes. PCs did not reliably discriminate trial type compared to CD (except for PC5). d. Explained variance along each dimension (see Methods). CD explained the most variance in the data (20.5 ± 2.3%). Explained variances for CD, CD+PC1+PC2, and CD+PC1~PC5 are shown. All error bars show bootstrapped standard error across units. e. Projections of neural activity as a function of time relative to the tone onset shown along PC3 (left), PC4 (middle) and PC5 (right). Data are shown for left- (top, blue) and right- (bottom, red) cued trials. The dotted lines show activity in no stim trials and thick lines that in stim trials. Light blue rectangle shows stimulation on window. f. Changes in activity during the stimulation window (100 ms) for each projection after stimulation (Δproject. modulation) along different dimensions during left- (blue) and right- (red) cued trials. Stimulation modulates activity the mostly along CD. P-values show significance of modulation (two-tailed t-test). g. similar analysis as panel f for iSPN inactivation (Main Fig.4, Extended Data Fig. 8d, see methods). P-values show significance of modulation (two-tailed t-test).
