The interposed nucleus is part of the deep cerebellar complex and is composed of the

globose nucleus The globose nucleus is one of the deep cerebellar nuclei. It is located medial to the emboliform nucleus and lateral to the fastigial nucleus. This nucleus contains primarily large and small multipolar neurons. The ''globose nucleus'' and embo ...

and the emboliform nucleus. It is located in the roof (dorsal aspect) of the

fourth ventricle The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and the fourth ...

, lateral to the fastigial nucleus. It receives its afferent supply from the anterior lobe of the cerebellum and sends output via the superior cerebellar peduncle to the

red nucleus The red nucleus or nucleus ruber is a structure in the rostral midbrain involved in motor coordination. The red nucleus is pale pink, which is believed to be due to the presence of iron in at least two different forms: hemoglobin and ferritin. ...

. The interposed nucleus is located in the paravermis of the cerebellum. 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 The posterior thoracic nucleus, (Clarke's column, column of Clarke, dorsal nucleus, nucleus dorsalis of Clarke) is a group of interneurons found in the medial part of lamina VII, also known as the intermediate zone, of the spinal cord. It is main ...

, respectively. The interposed nucleus is responsible for coordinating agonist/antagonist muscle pairs, and therefore a lesion in this area causes tremor. The interposed nucleus is smaller than the dentate but larger than the fastigial nucleus.

Function

Functionally, it modulates muscle stretch reflexes of proximal limb muscles. The cerebellar interpositus nucleus is also required in delayed Pavlovian conditioning.

References

External links

* https://web.archive.org/web/20080405060224/http://www.lib.mcg.edu/edu/eshuphysio/program/section8/8ch6/s8ch6_30.htm * http://www.neuroanatomy.wisc.edu/cere/text/P5/interp.htm Cerebellum {{neuroanatomy-stub