Detects and corrects movement errors

Compare intended vs. actual movement

Contributes to motor learning

There are 40x more projections to the cerebellum than from it

Extensive information regarding goals, commands, and feedback signals

Focused mainly on premotor and motor systems of brainstem and cortex

*No direct influence on lower motor neurons*

Damage to the cerebellum

(Ataxia)

Impaired balance, unsteady gait, and abnormal eye movements often accompanied by vertigo, nausea and vomiting

Impaired motor learning and certain cognitive functions

Does not alter sensory thresholds or strength of muscle contractions!!

Dentate (Most lateral)

Emboliform

Globos

Fastigial  (Most Medial)

1) Peduncles bring information into the cerebellar cortex

2)  Cerebellar cortex projects to the deep cerebellar nuclei

3)  Info is sent from deep cerebellar nuclei to the thalamus and brainstem

The primary afferent or incoming input

(Exception:  Efferent to the brainstem)

Primarily efferent or outgoing

(Exception:  Afferent, anterior spinocerebellar)

Mossy Fibers

Climbing Fibers:  from inferior olivary nucleus directly to the purkinje cell

Granular layer (innermost layer)

Purkinje cell layer (single layer of purkinje cell bodies)

Molecular layer (outermost layer)

Contains granule cells and Golgi interneurons

Mossy fibers terminate here

Is composed of purkinje cell bodies

The dendrites project into the molecular layer

Axons project to deep cerebellar nuclei and provide the main output of the cerebellar cortex

Contains the axons of the granule cells (parallel fibers) and dendrites of the purkinje cells

Also contains the stellate and basket cells (inhibit the purkinje cells)

1)Course from the spinal cord and brainstem to terminate in the granular layer

2)Carry sensory info from periphery and info from cerebral cortex

3)Excite the dendrites of granule cells

Originate in contralateral inferior olivary nuclei

Convey somatosensory, visual and cerebral cortical info

Excite the purkinje cells directly

Most lateral and largest deep nuclei

It receives input from the lateral hemisphere and from cerebellar afferents that carry information from the cerebral cortex (via the pontine nuclei).

It projects to the contralateral red nucleus and the ventrolateral (VL) thalamic nucleus.

Majority of cells in the cerebellum

Axons project to the cerebellar cortex to become parallel fibers

Parallel fibers excite the purkinje cells which in turn inhibit the deep nuclei

Vermis

Intermediate Zones

Lateral Hemispheres

1) Most medial cerebellar nucleus

2)  Receives input from vermis and from cerebellar afferents that carry vestibular, proximal somatosensory, auditory, and visual information.

3)  It projects to the vestibular nuclei and the reticular formation.

Composed of the emboliform and the globos nuclei

They receive input from the intermediate zone and from cerebellar afferents that carry spinal, proximal somatosensory, auditory, and visual information.

They project to the contralateral red nucleus (the origin of the rubrospinal tract).

Comprises the flocculonodular lobe and its connections with the lateral vestibular nuclei.

Phylogenetically, the vestibulocerebellum is the oldest part of the cerebellum.

As its name implies, it is involved in vestibular reflexes and in postural maintenance.

The spinocerebellum comprises the vermis and the intermediate zones of the cerebellar cortex, as well as the fastigial and interposed nuclei.

It receives major inputs from the spinocerebellar tract. Its output projects to rubrospinal, vestibulospinal, and reticulospinal tracts.

It is involved in the integration of sensory input with motor commands to produce adaptive motor coordination.

The largest functional subdivision of the human cerebellum, comprising the lateral hemispheres and the dentate nuclei.

Its name derives from its extensive connections with the cerebral cortex, via the pontine nuclei (afferents) and the VL thalamus (efferents).

It is involved in the planning and timing of movements. In addition, the cerebrocerebellum is involved in the cognitive functions of the cerebellum.