Nucleus raphe magnus
|Brain: Nucleus raphe magnus|
|Section of the medulla oblongata at about the middle of the olive. (Raphe nuclei not labeled, but 'raphe' labeled at left.)|
|Latin||nucleus raphes magnus|
This makes the magnus a likely candidate for part of the motor system; however, it seems to participate in the endogenous analgesia system.
The magnus receives descending afferents from the periaqueductal gray, the paraventricular hypothalamic nucleus, central nucleus of the amygdala, lateral hypothalamic area, parvocellular reticular nucleus and the prelimbic, infralimbic, medial and lateral precentral cortices .
All of these brain areas influence the main function of the raphe magnus.
The main function of the magnus is mostly pain mediation; in fact it sends projections to the dorsal horn of the spinal cord to directly inhibit pain.
Electrical stimulation of the PAG produces analgesia, as well as administration of morphine to the PAG or n.r. magnus.
All of this seems to indicate that the magnus is part of the endogenous opiate system, and acts to inhibit pain in the spinal cord.
- Hermann, Dirk M. et al. Afferent projections to the rat nuclei raphe magnus, raphe pallidus and reticularis gigantocellularis pars demonstrated by iontophoretic application of choleratoxin (subunit b). Journal of Chemical Neuroanatomy Volume 13, Issue 1 , June 1997, Pages 1-21