Red nucleus

{{distinguish|Red blood cell#Nucleus}}

{{short description|Structure in the human brain}}

{{Infobox Brain

| Name = Red nucleus

| Latin = nucleus ruber

| Image = Cn3nucleus-en.svg

| Caption = Transverse section through the midbrain showing the location of the red nuclei. The superior colliculi are at the top of image and the cerebral peduncles at the bottom of image – both in section.

| Image2 =

| Caption2 =

| IsPartOf = Midbrain

| Components =

| Artery =

| Vein =

}}

The red nucleus or nucleus ruber is a structure in the rostral midbrain involved in motor coordination.{{Cite journal| doi = 10.1038/s41598-019-48164-7| issn = 2045-2322| volume = 9| issue = 1| pages = 12117| last1 = Cacciola| first1 = Alberto| last2 = Milardi| first2 = Demetrio| last3 = Basile| first3 = Gianpaolo Antonio| last4 = Bertino| first4 = Salvatore| last5 = Calamuneri| first5 = Alessandro| last6 = Chillemi| first6 = Gaetana| last7 = Paladina| first7 = Giuseppe| last8 = Impellizzeri| first8 = Federica| last9 = Trimarchi| first9 = Fabio| last10 = Anastasi| first10 = Giuseppe| last11 = Bramanti| first11 = Alessia| last12 = Rizzo| first12 = Giuseppina| title = The cortico-rubral and cerebello-rubral pathways are topographically organized within the human red nucleus| journal = Scientific Reports| date = 2019-08-20| pmid = 31431648| pmc = 6702172| bibcode = 2019NatSR...912117C}} 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.{{Cite journal| doi = 10.2214/ajr.147.1.103| issn = 0361-803X| volume = 147| issue = 1| pages = 103–110| last1 = Drayer| first1 = B.| last2 = Burger| first2 = P.| last3 = Darwin| first3 = R.| last4 = Riederer| first4 = S.| last5 = Herfkens| first5 = R.| last6 = Johnson| first6 = G. A.| title = MRI of brain iron| journal = AJR. American Journal of Roentgenology| date = July 1986| pmid = 3487201}} The structure is located in the midbrain tegmentum next to the substantia nigra and comprises caudal magnocellular and rostral parvocellular components. The red nucleus and substantia nigra are subcortical centers of the extrapyramidal motor system.

Function

In a vertebrate without a significant corticospinal tract, gait is mainly controlled by the red nucleus.{{Cite journal| doi = 10.1016/0166-4328(88)90072-1| issn = 0166-4328| volume = 28| issue = 1| pages = 9–20| last = ten Donkelaar| first = H. J.| title = Evolution of the red nucleus and rubrospinal tract| journal = Behavioural Brain Research| date = 1988-04-01| pmid = 3289562| s2cid = 54367413}} However, in primates, where the corticospinal tract is dominant, the rubrospinal tract may be regarded as vestigial in motor function. Therefore, the red nucleus is less important in primates than in many other mammals.{{Cite journal| doi = 10.1371/journal.pone.0006623| issn = 1932-6203| volume = 4| issue = 8| pages = –6623| last1 = Onodera| first1 = Satoru| last2 = Hicks| first2 = T. Philip| title = A Comparative Neuroanatomical Study of the Red Nucleus of the Cat, Macaque and Human| journal = PLOS ONE| date = 2009-08-13| pmid = 19675676| pmc = 2722087| bibcode = 2009PLoSO...4.6623O| s2cid = 18760268| doi-access = free}} Nevertheless, the crawling of babies is controlled by the red nucleus, as is arm swinging in typical walking.{{cite book|title=Being and Perceiving|url=https://books.google.com/books?id=fXFeQb1z6bsC&pg=PA49|year=2011|publisher=Manupod Press|isbn=978-0-9569621-0-2|pages=49}} The red nucleus may play an additional role in controlling muscles of the shoulder and upper arm via projections of its magnocellular part.{{Cite journal| doi = 10.1113/jphysiol.1985.sp015565| issn = 1469-7793| volume = 358| issue = 1| pages = 527–549| last1 = Gibson| first1 = A. R.| last2 = Houk| first2 = J. C.| last3 = Kohlerman| first3 = N. J.| title = Magnocellular red nucleus activity during different types of limb movement in the macaque monkey.| journal = The Journal of Physiology| date = 1985| pmid = 3981472| pmc = 1193356}}{{Cite journal| doi = 10.1007/s00221-001-0924-5| issn = 1432-1106| volume = 142| issue = 1| pages = 151–157| last1 = van Kan| first1 = Peter L.| last2 = McCurdy| first2 = Martha L.| title = Discharge of primate magnocellular red nucleus neurons during reaching to grasp in different spatial locations| journal = Experimental Brain Research| date = 2002-01-01| pmid = 11797092| s2cid = 42113292}} In humans, the red nucleus also has limited control over hands, as the rubrospinal tract is more involved in large muscle movement such as that for the arms (but not for the legs, as the tract terminates in the superior thoracic region of the spinal cord). Fine control of the fingers is not modified by the functioning of the red nucleus but relies on the corticospinal tract.{{Cite journal| doi = 10.1523/JNEUROSCI.0390-14.2014| issn = 1529-2401| volume = 34| issue = 21| pages = 7341–7350| last1 = Bunday| first1 = Karen L.| last2 = Tazoe| first2 = Toshiki| last3 = Rothwell| first3 = John C.| last4 = Perez| first4 = Monica A.| title = Subcortical Control of Precision Grip after Human Spinal Cord Injury| journal = Journal of Neuroscience| date = 2014-05-21| url= | pmid = 24849366| pmc = 4028504}} The majority of red nucleus axons do not project to the spinal cord but, via its parvocellular part, relay information from the motor cortex to the cerebellum through the inferior olivary complex, an important relay center in the medulla.

Input and output

The red nucleus receives many inputs from the cerebellum (interposed nucleus and the lateral cerebellar nucleus) of the opposite side and an input from the motor cortex of the same side.{{Cite journal| doi = 10.1016/j.neulet.2016.05.009| issn = 0304-3940| volume = 626| pages = 68–73| last1 = Milardi| first1 = Demetrio| last2 = Cacciola| first2 = Alberto| last3 = Cutroneo| first3 = Giuseppina| last4 = Marino| first4 = Silvia| last5 = Irrera| first5 = Mariangela| last6 = Cacciola| first6 = Giorgio| last7 = Santoro| first7 = Giuseppe| last8 = Ciolli| first8 = Pietro| last9 = Anastasi| first9 = Giuseppe| last10 = Calabrò| first10 = Rocco Salvatore| last11 = Quartarone| first11 = Angelo| title = Red nucleus connectivity as revealed by constrained spherical deconvolution tractography| journal = Neuroscience Letters| access-date = 2020-08-30| date = 2016-07-28| pmid = 27181514| s2cid = 46756208| url = http://www.sciencedirect.com/science/article/pii/S0304394016303081| url-access = subscription}}

The red nucleus has two sets of efferents:

  • In humans, the majority of the output goes to the bundle of fibers continues through the medial tegmental field toward the inferior olive of the same side, to form part of a pathway that ultimately influence the cerebellum.
  • The other output (the rubrospinal projection) goes to the rhombencephalic reticular formation and spinal cord of the opposite side, making up the rubrospinal tract, which runs ventral to the lateral corticospinal tract. As stated earlier, the rubrospinal tract is more important in non-primate species: in primates, because of the well-developed cerebral cortex, the corticospinal tract has taken over the role of the rubrospinal.

See also

Additional images

File:Gray678.png|Schematic representation of the chief ganglionic categories (I to V).

File:Gray690.png|Deep dissection of brain-stem. Ventral view.

File:Weber's syndrome.svg

File:Slide11kk.JPG|Red nucleus

References

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