Chapter 19 - Modulation of Movement by the Cerebellum

cerebrocerebellum

lateral part of the cerebellar hemisphere, greatly expanded in humans, that receives input from the cerebral cortex via axons from the pontine relay nuclei and sends output to the promotor and prefrontal cortex via the thalamus; concerned with planning and execution of complex spatial temporal sequences of skilled movement

spinocerebellum

medial part of the cerebellum that receives proprioceptive input from the spinal cord and sends output to the motor cortex via the thalamus and brainstem upper motor neurons; includes paramedian zones that coordinate movements of distal muscles, and a median zone, called the vermis, that coordinate movements of proximal muscles, including eye movements

vermis

median zone of the spinocerebellum that receives proprioceptive input from the spinal cord and sends output to brainstem upper motor neurons; coordinates movements of proximal muscles, including eye movements

vestibulocerebellum

caudal-inferior lobes of the cerebellum, including the flocculus and nodulus, that receives input from the vestibular nuclei in the brainstorm and the vestibular nerves; concerned with the vestibulo-ocular reflex and the coordination of movements that maintain posture and equilibrium

flocculus

lateral portion of the vestibulocerebellum that receives input from the vestibular nuclei in the brainstem and the vestibular nerve; coordinates the vestibulo-ocular reflex and movements that maintain posture and equilibrium

nodulus

medial portion of the vestibulocerebellum that receives inout from the vestibular nuclei in the brainstem and the vestibular nerve; coordinates the vestibulo-ocular reflex and movements that maintain posture and equilibrium

cerebellar peduncles

three bilateral pairs of tracts that convey axons to and from the cerebellum. the superior cerebellar peduncle, or brachium conjunctivum, is primarily an efferent motor pathway; the middle cerebellar peduncle, or brachium pontis, is an afferent pathway arising from the pontine nuclei. the smallest but most complex is the inferior cerebellar peduncle, or restiform body, which encompasses multiple afferent and efferent pathways

deep cerebellar nuclei

subcortical nuclei at the base of the cerebellum that give rise to output from the cerebellum to the thalamus and brainstem; integrate afferent signals to the cerebellum and cortical processing conveyed by Purkinje neurons

pontine nuclei

collections of neurons in the base of the pons that receive input from the ipsilateral cerebral cortex and send their axons across the midline to the contralateral cerebellum via the middle cerebellar peduncle

mossy fibers

afferent axons to the cerebellum from all sources except for the inferior olivary nuclei; the vast majority enter the cerebellum via the inferior and middle cerebellar peduncles

parallel fibers

the bifurcated axons of cerebellar granule cells that extend along the length of the folia in the molecular layer of the cerebellar cortex where they synapse on dendritic spines of Purkinje cells

climbing fibers

axons that originate in the inferior olivary nuclei, ascend through the inferior cerebellar peduncle, and make terminal arborizations that invest the proximal dendritic trees of Purkinje cells; induce complex spikes and long-term depression in cerebellar Purkinje neurons

basket cells

inhibitory interneurons in the cerebellar cortex whose cell bodies are located within the Purkinje cell layer and whose axons make basket-like terminal arbors around Purkinje cell bodies, providing lateral inhibition that focuses the spatial distribution of Purkinje cell activity

stellate cells

inhibitory interneurons in the cerebellar cortex that receive parallel fiber input and provide inhibitory output to the Purkinje cell dendrites

Golgi cells

inhibitory interneurons in the granular cell layer of the cerebellar cortex that provide inhibitory feedback from parallel fibers to granule cells, regulating the temporal properties of the granule cell input to the Purkinje cells