Extended Data Figure 8 : Granule cell reward responses during a Pavlovian tone–reward task.

From: Cerebellar granule cells encode the expectation of reward

Extended Data Figure 8

ac, Average reward-aligned fluorescence of all reward preferring cells (a), reward-omission cells (b) and reward-anticipation cells (c), from all mice and lobules during the tone–reward task (n = 23 reward, 42 reward omission, and 25 reward anticipation cells from 11 experiments in 5 mice). On average, reward anticipation neurons were silent following unexpected reward (P = 0.24 Wilcoxon signed-rank test; mean fluorescence change of –0.05 ± 0.05 s.d. comparing 0 – 1 s to –0.25 to –0.05 s relative to unexpected reward, n = 25 neurons). Reward-omission cells did not distinguish expected from unexpected reward (P = 0.48 Wilcoxon signed-rank test comparing mean fluorescence from 0 to 1 s, n = 42 reward omission neurons). Dashed vertical lines indicate time of tone onset. d, Scatter of response properties of individual neurons (coloured dots) showing reward preference (x axis) versus licking sensitivity (y axis) during the tone–reward task (n = 450 neurons). e, Single-trial correlation between licking and activity of each reward anticipation neuron either before reward delivery, after reward omission, or after reward delivery, averaged across all reward anticipation neurons during the Pavlovian task (n = 25 reward anticipation neurons from 11 experiments in 5 mice; P = 0.02 pre-reward, P = 0.015 post-omitted-reward, P = 0.72 post-reward; Wilcoxon signed-rank test). As during forelimb movements, reward-anticipation neurons correlate with licking only when licking represents anticipation. Following reward, when anticipation ceases, licking exerts no effect on activity. f, A subset of cells exhibited decreased fluorescence following the tone. To determine what these cells might be encoding, we identified all such neurons (Methods) and examined their response on the various trial types. We determined that these cells remain inhibited while the mouse is licking, beginning with anticipatory licking through reward consumption (n = 20 cells from 5 mice). Importantly, on unexpected reward trials, these neurons are also inhibited. This is unlike reward-anticipation cells in c that cease to be active following reward delivery and also remain silent on surprise reward trials. Thus cells inhibited by licking are more classically sensorimotor. g, Top, trials with a normal sized reward compared to randomly interspersed trials with an larger reward. Bottom, normal reward trials compared to trials with the most and least reward licking. h, Plot of each cell’s response difference between normal and large rewards (x axis) and preference for licking on normal reward trials (y axis). Dashed boxes indicate reward magnitude sensitive neurons without substantial licking sensitivity. Example cell from g is outlined. i, Each row shows the trial-averaged Ca2+ response of a single neuron. Cells in each panel (trial types indicated above) are ordered identically based on their response on rewarded trials (n = 135 neurons from three sessions in lobules VIa, VIb and simplex from an example mouse).