The cerebellum is essential for motor coordination and to learn new motor skills. In the cerebellar cortex, information processing is based on a modular organization: each module is involved in the control of specific motor units. Localized lesions of the cerebellum impair coordinated movements in only one part of the body and lead to movement disorders like ataxia. This project aims to understand how cerebellar modules communicate, process incoming information and how they relate to coordinated movements in mice. We combine optical and electrophysiological approaches in vitro in order to determine the functional synaptic maps between different modules. The development of these maps revealed that the establishment of connections between distant modules coincide with the appearance of motor coordination in mice. Using models of motor alteration, we showed that synaptic maps are reorganized following motor adaptation. The results bring new hypotheses about the control of motor coordination in normal and pathological conditions. Future directions will be to assess how a specific activation of identified modules may compensate for motor impairments.