Processing reliant on granule cells is essential for motor learning but dispensable for social preference and numerous other cerebellar-dependent behaviors

Abstract Mossy fiber inputs are transformed into cerebellar Purkinje cell (PC) outputs by granule cell (GC)-dependent processing. Cerebellar dysfunction leads to motor, learning, emotional, and social deficits that are usually attributed to altered PC firing arising from impaired processing of mossy fiber inputs, even though PCs also fire independently of GCs. To isolate their contributions to cerebellum-dependent behaviors, we either disrupt GC signaling while leaving PC firing intact, or disrupt PC signaling to eliminate the influence of PCs. Experiments were