SUMMARY
The cerebellum integrates sensory stimuli and motor actions to enable smooth coordination and motor learning. We use population imaging and single-cell electrophysiology while monitoring behavior to find the neural correlates of sensory and motor variables in the cerebellar Purkinje cell population during visually-driven behaviors in larval zebrafish. We find that Purkinje cells functionally cluster into three regions that receive similarly tuned, sensory climbing fiber input relating to distinct visual features. In contrast, the simple spike output of nearly all Purkinje cells is strongly driven by motor-related tail and eye signals. At rest, complex spikes modulate simple spike rates over hundreds of milliseconds in a cell-specific way, whereas during swimming, complex spikes have a very acute temporal effect on already high simple spike rates. Our findings highlight the importance of motor context for cerebellar computations and provide the first comprehensive description of sensorimotor coding across the Purkinje cell population during behavior.