Developmental emergence of spatiotemporal coordination in cerebellar Purkinje cell populations
Coordinated activity across neuronal populations is fundamental to brain function, yet how such network-level organization emerges during development remains incompletely understood. Here, we performed whole-cerebellar calcium imaging at cellular scale in zebrafish larvae to examine the developmental maturation of Purkinje cell population dynamics. Visual stimulation recruited large, spatially organized populations of Purkinje cells whose responses depended on inferior olive input and were associated with optokinetic behavior. Notably, in the absence of stimuli, Purkinje cells formed transient assemblies exhibiting distance-dependent coordination. During development, long-range coordination progressively emerged, extending initially local correlations into distributed population-wide coordination. Early enucleation, but not dark rearing, disrupted the developmental refinement of long-range coordination and induced aberrant population clustering, suggesting that early retina-dependent signals contribute to cerebellar network development. Together, these findings reveal key organizational features underlying the developmental emergence of coordinated cerebellar population dynamics and suggest that early retina-dependent signals shape population-level organization.