ABSTRACT

The cerebellum has a major role in the execution of voluntary movements, both postural and limb movements, particularly those involving several joints. By comparing command signals generated by the motor cortex and red nucleus with proprioceptor feedback from muscles and joints, it acts to correct differences that arise between motor intention and motor performance. The proprioceptor pathway from the lower trunk and legs is distinct from that serving the upper body. Nucleus Z neurons send their axons into the medial lemniscus and thereby provide input for conscious lower body proprioception. The ventral spinocerebellar tract arises from the ventral horn and transmits signals reflecting the activity of spinal interneurons that are driven by motor commands regulating locomotor cycles. Hence the VST informs the cerebellum about the state of spinal cord central pattern generators. Over the surface of the cerebellum lies the cerebellar cortex which is folded into coronal strips called folia (singular, folium).