Purkinje cell intrinsic activity shapes cerebellar development and function

The emergence of functional cerebellar circuits is heavily influenced by activity-dependent processes. However, the role of intrinsic activity in Purkinje neurons, independent of external input, in driving cerebellar development remains less understood. Here, we demonstrate that before synaptic networks mature, Purkinje cell intrinsic activity is essential for regulating dendrite growth, establishing connections with cerebellar nuclei, and ensuring proper cerebellar function. Disrupting this activity during the postnatal period impairs motor function, with earlier disruptions causing more severe effects. Importantly, only disruptions during early development lead to pronounced defects in cellular morphology, highlighting key temporal windows for dendritic growth and maturation. Transcriptomic analysis revealed that early intrinsic activity drives the expression of activity-dependent genes, such as Prkcg and Car8, which are essential for dendritic growth. Our findings emphasize the importance of temporally-specific intrinsic activity in Purkinje cells for guiding cerebellar circuit development, providing a potential common mechanism underlying cerebellum-related disorders.