Fig. 2: Encoding of saccade kinematics by mossy fibers (MFs).

a Raster plots (up) and average firing histogram (bottom) of a representative burst-tonic (purple), short-lead burst (yellow) and long-lead burst (turquoise) MF unit. Solid gray lines between upper and lower panels are the mean horizontal eye position traces. Data are aligned to saccade onset. b Proportion of MF units in each category. c–e Population response of burst-tonic (purple), short-lead burst (yellow) and long-lead burst (turquoise) MFs to high and low velocity saccades (see insets for average velocity profiles), represented by lighter and darker shades, respectively. Solid lines represent the mean and the shaded regions are ±SEM. f, h, j Average peak firing rate as a linear function of saccade peak velocity (bin size = 50 deg/s) for each MF category. Linear regression parameters: Burst-tonic (f): p = 0.016, R² = 0.83; Short-lead burst (h): p = 0.005, R² = 0.9; Long-lead burst (j): p = 0.006, R² = 0.9. g, i, k Average burst offset relative to saccade onset as a function of saccade duration (calculated from velocity bins) for each MF category. Linear regression parameters: Burst-tonic (g): p = 0.008, R² = 0.88; Short-lead burst (i): p = 0.0005, R² = 0.96; Long-lead burst (k): p = 0.0005, R² = 0.97. Solid gray lines represent the linear regression fits. Light and dark-colored bins correspond to the high and low peak velocity bins, respectively, for which population responses in c, d and e are plotted for comparison. Data are mean ± SEM obtained from n = 24 burst-tonic, n = 60 long-lead burst and n = 27 short-lead burst units, respectively.