[3] The interposed nucleus is responsible for coordinating agonist/antagonist muscle pairs, and therefore a lesion in this area causes tremor.
[citation needed] The interposed nuclei receives Purkine cell terminal afferents from the paravermal cortex of the spinocerebellum, as well as collaterals of cerebellar afferents from the restiform body and ventral spinocerebellar tract.
[2] It receives input from the ipsilateral posterior external arcuate fibers (cuneocerebellar tract) and the dorsal spinocerebellar tract, which originate in the accessory cuneate nucleus and the posterior thoracic nucleus, respectively.
[citation needed] Afferents from the interposed nuclei leave the cerebellum through superior cerebellar peduncle.
They project to:[2] The rubrospinal and lateral corticospinal tracts are subsequently involved in control of the distal musculature of the extremities.