Three fiber bundles (superior, middle, inferior) that facilitate communication between the cerebellum, brainstem, and other areas of the central nervous system. They allow for integration of sensory and motor information. Afferent fibers send information to the cerebellar peduncles from the spinal cord, cerebral cortex, and vestibular nerve. Efferent fibers from the deep cerebellar nuclei pass through the cerebellar peduncles to the thalamus, red nucleus, reticular formation, and vestibular nucleus.