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The ability of the brain to accurately control a movement depends on the cerebellum. Yet, how the cerebellar neurons encode information relevant for this control remains poorly understood. The computations that are performed in the cerebellar cortex are transmitted to its nuclei via Purkinje cells (P cells), which are inhibitory neurons. However, if the spiking activity within P cell populations were temporally synchronized, that inhibition would entrain nucleus neurons, making them fire. Do P cells transmit information by synchronously timing their spikes? We simultaneously recorded from multiple P cells while marmosets performed saccadic eye movements, and organized the neurons into populations that shared a complex spike response to error. Before movement onset, this population of P cells increased their simple spike activity with a magnitude that depended on the velocity of the upcoming saccade, and then sharply reduced their activity below baseline at saccade onset. During deceleration, the spikes became temporally aligned within the population. Thus, the P cells relied on disinhibition, combined with spike synchronization, to convey to the nucleus when to decelerate and potentially stop the movement. [ABSTRACT FROM AUTHOR]

Computations that are performed by the cerebellar cortex are transmitted via simple spikes of Purkinje cells (P-cells) to downstream structures, but because P-cells are many synapses away from muscles, we do not know the relationship between modulation of simple spikes and control of behavior. Here, we recorded the spiking activities of hundreds of P-cells in the oculomotor vermis of marmosets during saccadic eye movements and found that following the presentation of a visual stimulus, the olivary input to a P-cell coarsely described the direction and amplitude of the visual stimulus as well as the upcoming movement. Occasionally, the complex spike occurred just before saccade onset, suppressing the P-cell's simple spikes and disrupting its output during that saccade. Remarkably, this brief suppression of simple spikes altered the saccade's trajectory by pulling the eyes toward the part of the visual space that was preferentially encoded by the olivary input to that P-cell. Thus, there is an alignment between the sensory space encoded by the complex spikes and the behavior conveyed by the simple spikes: a reduction in simple spikes is a signal to bias the ongoing movement toward the part of the sensory space preferentially encoded by the olivary input to that P-cell. [Display omitted] • Complex spikes encode events in a specific region of the visuomotor space • Suppression of P-cell output by a complex spike pulls the eye toward "CS-on" • Complex spike activity reflects stimulus location and movement direction • P-cell output is aligned with visual rather than muscle coordinates Muller, Pi, et al. show that a brief suppression of cerebellar Purkinje-cell output by a complex spike consistently perturbs saccadic eye movement by pulling the eye toward the part of the sensory space encoded by the olivary input to that Purkinje cell. These results reveal how a P-cell is affecting downstream behaviors. [ABSTRACT FROM AUTHOR]