Cerebellum: Projections
All efferent/afferent projections from the cerebellum go through the three peduncles: superior, middle, inferior peduncles. The projections from the spinal cord come via superior/inferior peduncles (anterior/posterior spinocerebellar tract) to paleocerebellum. The cerebrum cortex synapse at pons sends its projections to the neocerebellum via middle peduncle. The cerebrum - pons - cerebellum - thalamus loop processes the fine tuning of a movement. The vestibular nuclei sends its axons through inferior peduncle to archicerebellum.
Afferent Projections
All the afferent axons of cerebellum synapse at cerebellar nuclei by axon collateral. The projections from the spinal cord (anterior spinocerebellar tract) and locus coruleus (neurotransmitter: norepinephrine) go through the superior cerebellar peduncle. The pontine nuclei sends its axons to cerebellum through middle cerebellar peduncle. The inferior cerebellar peduncle receives projections from spinal cord, vesibular nuclei, inferior olive, lateral reticular nuclei, and head.
| Peduncle | Destination | Tract |
|---|---|---|
| Superior Cerebellar Peduncle | spinal cord | anterior spinocerebellar tract |
| locus coruleus | ||
| Middle Cerebellar Peduncle | pontine nuclei | pontocerebellar tract |
| Inferior Cerebellar Peduncle | spinal cord | posterior spinocerebellar tract |
| spinal cord | cuneocerebellar tract | |
| vestibular nuclei | vestibulocerebellar tract | |
| inferior olive | olivocerebellar tract | |
| lateral reticular nuclei | reticulocerebellar tract | |
| head(face) | trigeminocerebellar tract |
Efferent Projections
The efferent fibers synapse at cerebellar nuclei except for cerebellovestibular fibers. The fibers from VL nuclei of thalamus, red nuclei, and medulla projects to cerebellum through superior cerebellar peduncle. The inferior and medial vestibular nuclei sends its axons to archicerebellum through inferior cerebellar peduncle.
| Peduncle | Origin | Tract |
|---|---|---|
| Superior Cerebellar Peduncle | VL nuclei of thalamus | cerebellodentatothalamic tract |
| red nuclei | cerebellodentatorubral tract | |
| medulla | fastigiobulbar tract | |
| Inferior Cerebellar Peduncle | inferior/medial vestibular nuclei | cerebellovestibular tract |