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 embol ...

and the

emboliform nucleus The emboliform nucleus (or anterior interposed nucleus) is a deep cerebellar nucleus that lies immediately to the medial side of the nucleus dentatus, and partly covering its hilum. It is one among the four pairs of deep cerebellar nuclei, whi ...

. 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 The fastigial nucleus is located in the cerebellum. It is one of the four deep cerebellar nuclei (the others being the nucleus dentatus, nucleus emboliformis and nucleus globosus), and is grey matter embedded in the white matter of the cereb ...

. It receives its afferent supply from the anterior lobe of the cerebellum and sends output via the

superior cerebellar peduncle In the human brain, the superior cerebellar peduncle (brachium conjunctivum) is a paired structure of white matter that connects the cerebellum to the midbrain. It consists mainly of efferent fibers, the cerebellothalamic tract that runs from a cer ...

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 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 ...

(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 The accessory cuneate nucleus is located lateral to the cuneate nucleus in the medulla oblongata at the level of the sensory decussation (the crossing fibers of the posterior column/ medial lemniscus tract). It receives sensory input about positi ...

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 Classical conditioning (also known as Pavlovian or respondent conditioning) is a behavioral procedure in which a biologically potent stimulus (e.g. food) is paired with a previously neutral stimulus (e.g. a triangle). It also refers to the learni ...

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