The interposed nucleus is part of the
deep cerebellar complex and is composed of the
globose nucleus 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 ve ...
, 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
The spinocerebellar tract is a nerve tract originating in the spinal cord and terminating in the same side (ipsilateral) of the cerebellum.
Origins of proprioceptive information
Proprioceptive information is obtained by Golgi tendon organs and ...
, which originate in the
accessory cuneate nucleus and the
posterior thoracic nucleus, 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
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