Medial prefrontal cortex encodes implicit temporal expectations in mice

Temporal prediction allows animals to align their actions with upcoming events, yet most work has focused on explicit duration judgments rather than the implicit timing that shapes ongoing behavior. Here, we ask how medial prefrontal cortex implements such latent temporal expectations and how cerebellar input contributes. Head-fixed mice learned a cued water-delivery task in which reward occurred after either a short or long delay, or after a single fixed delay. During variable delays, running and licking became anticipatory, and medial prefrontal local field potentials and single neurons showed ramping and reward-locked activity patterns aligned to expected reward time. Switching to a fixed delay rapidly sharpened behavioral anticipation and temporal coding. Optogenetic activation of cerebellar Purkinje cells selectively perturbed these dynamics and biased behavior around the earliest possible reward time. These results identify a cerebello-prefrontal circuit that encodes implicit temporal predictions on the sub-second scale.