LAB 10 CEREBELLUM In order to function in

LAB #10: CEREBELLUM

In order to function in coordinating precise timing and sequencing of movements, the cerebellum must process information from many sources before sending “corrections” to upper motor neuron systems. Input comes to the cerebellum via the inferior cerebellar peduncle from: vestibular receptors body surface & muscle receptors the inferior olive Input comes to the cerebellum via the middle cerebellar peduncle from: widespread areas of cerebral cortex (after a synapse in pontine nuclei) Outflow from the cerebellum reaches upper motor neuron systems via the superior cerebellar peduncle for: -cerebral cortex, especially SMA (after a synapse in the thalamus) -the red nucleus Outflow from the cerebellum to brainstem upper motor neurons that regulate proximal muscles (vestibular nuclei, reticular nuclei) travels through the inferior peduncle.

OVERVIEW OF INTRINSIC CONNECTIONS OF THE CEREBELLUM Axons that enter the cerebellum as climbing fibers (from inferior olivary nuclei) or mossy fibers (all other input) terminate in: cerebellar cortex deep nuclei of cerebellum Impulse transmission through the cerebellar cortex includes: - termination of climbing fibers on Purkinje cell dendrites & deep cerebellar nuclei; - termination of mossy fibers on granule cells & deep nuclei; - ascent of granule cell axons as parallel fibers in molecular layer; - termination of parallel fibers on Purkinje cells; - descent of Purkinje cell axons to deep cerebellar nuclei

Haines 2 -31 1) vestibulocerebellum = flocculonodular lobe -> balance & eye movement; 2) spinocerebellum = vermis (medial zone) + intermediate hemisphere (zone) -> adjustments for smooth movement of proximal (vermis) and distal (intermediate cortex) limb movement; 3) cerebrocerebellum = lateral hemisphere (zone) -> motor planning

Haines 2 -33

Haines 2 -30

Haines 5 -15 Cerebellar cortex Cerebellar white mater Deep cerebellar nuclei Fastigial nucleus Interposed nuclei Dentate nucleus

Blackboard 4 Cerebellar cortex Molecular Layer Granular layer ter at te M Whi Cerebellar white matter

Blackboard 5 molecular layer Purkinje layer granule layer

Haines 5 -11 Olivocerebellar fibers – cerebrocerebellum receives fibers from contralalteal ION Vestibular Nuclei Reticular Form Inf Olivary Nucleus Midrostral Medulla Level Inf Cerebellar peduncle

Haines 5 -12 Olivocerebellar fibers Vestibular Nuclei Inf Olivary Nucleus Rostral Medulla Level Inf Cerebellar peduncle

Corticopontine fibers C or t F icos ib p er in s al Corticobulbar fibers Rostral Midbrain Level Haines 5 -25

Haines 5 -18 Middle Cerebellar Peduncle Pontine Nuclei Pontocerebellar fibers Rostral Pons Level

Haines 5 -19 Sup. Cerebellar peduncle Rostral Pons Level

Haines 5 -20 Sup. Cerebellar peduncle Rostral Pons Level

Haines 5 -22 Sup. Cerebellar peduncle decussation Pons/midbrain jctn Level

Haines 5 -23 Sup. Cerebellar peduncle decussation Caudal Midbrain Level

Haines 5 -25 Cerebellothalamic fibers Red Nucleus Rostral Midbrain Level Red Nucleus

Haines 5 -26 Rostral Midbrain Level

Haines 5 -32 thalamus