Persistent activity of cerebellar molecular layer interneurons facilitates anticipatory control of tongue movements

Precise, anticipatory movements depend on the brains ability to generate motor commands in advance of immediate sensory input. Although the cerebellar cortex receives abundant sensory input via the mossy-fiber pathway, the mechanisms by which continuous sensory signals are transformed or gated remain poorly understood. Here, we show that molecular layer interneurons acquire persistent sensory-related Ca2+ activity in mice that develop anticipatory behavior. Employing a targeted lick-interception task, we found that interneurons in lobule Crus I, but much less in Crus II, exhibit enhanced Ca2+ activity up to five seconds before movement onset, locked to the spatial position of a continuously moving target, independent of body movement. In more anticipatory mice, movement onset becomes linked to the dynamics of this persistent activity, whereas less anticipatory mice adjust their movements based on immediate sensory-related input. Our results indicate that anticipation in sensorimotor tasks is supported by dynamic sensory representations encoded by interneurons.