The cerebellum plays a fundamental role in motor control in humans, contributing to coordination, precision of movements, and accurate timing of muscle activities. It receives sensory inputs from the spinal cord and integrates these inputs to fine-tune motor activity via multiple loops with the cerebral cortex and brainstem. The two main afferent paths to the cerebellum are the mossy fibers and the climbing fibers, which both project to the cerebellar cortex and nuclei. The activation of Purkinje cells results in inhibition of cerebellar nuclei, consequently reducing excitatory input on the motor cortex via the dentato-thalamo-cortical pathway. The facilitatory/disfacilitatory effect of cerebellar nuclei upon remote targets is an essential mode of action of the cerebellar circuitry.
