Nucleus raphe magnus

Nucleus raphe magnus
Brain: Nucleus raphe magnus
Gray694.png
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
NeuroNames hier-736
NeuroLex ID birnlex_1363

The nucleus raphes magnus, located directly rostral to the nucleus raphes obscurus, is afferently stimulated from axons in the spinal cord and cerebellum.

This makes the nucleus raphes magnus a likely candidate for part of the motor system; however, it seems to participate in the endogenous analgesia system. Mounting evidence suggests that the nucleus raphes magnus plays an important role in homeostatic regulation [1][2].

The nucleus raphes 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 [3].

All of these brain areas influence the main function of the nucleus raphes magnus.

The main function of the nucleus raphes magnus is mostly pain mediation; in fact it sends projections to the dorsal horn of the spinal cord to directly inhibit pain. The nucleus raphes magnus releases enkephalin when stimulated.

The periaqueductal gray, the epicenter of analgesia, sends efferent connections to the nucleus raphes magnus in when it is stimulated by opiates (endogenous or otherwise).

Electrical stimulation of the PAG produces analgesia, as well as administration of morphine to the PAG or nucleus raphes magnus.

The antinociceptic effects of electrical stimulation of the PAG can be blocked by administering naloxone, an opiate antagonist, to the nucleus raphes magnus.

All of this seems to indicate that the nucleus raphes magnus is part of the endogenous opiate system, and acts to inhibit pain in the spinal cord.

See also

References

  1. ^ Hellman, Kevin et al. Activity of murine magnus raphe cells predicts tachypnea and on-going nociceptive responsiveness. Journal of Neurophysiology Volume 98, Issue 6, December 2007, Pages 3121-33.
  2. ^ Hellman, Kevin et al., Opioid microinjection into raphe magnus modulates cardiorespiratory function in mice and rats. American Journal of Physiology Regulator Integratory Comp Physiology. Volume 297, Issue 5, November 2009, Pages R1400-8.
  3. ^ Hermann, Dirk M. et al. Afferent projections to the rat nuclei raphes magnus, raphes 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
v · d · eHuman brain: rhombencephalon, myelencephalon: medulla (TA A14.1.04, GA 9.767)
Dorsal
Surface
Grey: other
White: Sensory/ascending
White: Motor/descending
Ventral
White: Motor/descending
Surface
Anterior median fissure · Anterolateral sulcus · Olive · Pyramid
Grey: Raphe/
reticular

M: CNS

anat(n/s/m/p/4/e/b/d/c/a/f/l/g)/phys/devp

noco(m/d/e/h/v/s)/cong/tumr, sysi/epon, injr

proc, drug(N1A/2AB/C/3/4/7A/B/C/D)

Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Nucleus raphe pallidus — Brain: Nucleus raphe pallidus Section of the medulla oblongata at about the middle of the olive. (Raphe nuclei not labeled, but raphe labeled at left.) Latin nucleus raphes pallidus NeuroNames …   Wikipedia

  • Nucleus raphe obscurus — Brain: Nucleus raphe obscurus Section of the medulla oblongata at about the middle of the olive. (Raphe nuclei not labeled, but raphe labeled at left.) Latin nucleus raphes obscurus NeuroNames …   Wikipedia

  • nucleus raphes magnus — [TA] magnus raphe nucleus: a raphe nucleus partially overlapping the nucleus pallidus and nucleus obscurus in the medulla oblongata and projecting upward into the caudal pons; its neurons are serotoninergic …   Medical dictionary

  • Raphe nuclei — Infobox Brain Name = PAGENAME Latin = nuclei raphes GraySubject = GrayPage = Caption = Section of the medulla oblongata at about the middle of the olive. (Raphe nuclei not labeled, but raphe labeled at left.) Caption2 = IsPartOf = Components =… …   Wikipedia

  • raphe nuclei — nuclei raphes [TA] the median column reticular nuclei, a subgroup of the reticular nuclei of the brainstem, found in narrow longitudinal sheets along the raphae of the medulla oblongata, pons, and mesencephalon; they include many neurons that… …   Medical dictionary

  • Dorsal raphe nucleus — Brain: Dorsal raphe nucleus Outline of the nucleus raphe dorsalis: DRif interfascicular subnucleus, DRv ventral subnucleus, DRvl ventrolateral subnucleus, DRd dorsal subnucleus, mlf medial longitudinal fasciculus, Aq cerebral aqueduct, IVn… …   Wikipedia

  • Nucleus — 1) In cell biology, the structure that houses the chromosomes. 2) In neuroanatomy, a group of nerve cells. * * * 1. In cytology, typically a rounded or oval mass of protoplasm within the cytoplasm of a plant or animal cell; it is surrounded by a… …   Medical dictionary

  • Nucleus ambiguus — Brain: Nucleus ambiguus Transverse section of medulla oblongata below the middle of the olive. ( Nucleus ambiguus labeled at center right.) Gray s subject #187 …   Wikipedia

  • Nucleus prepositus hypoglossi — Located in the medulla, the nucleus prepositus hypoglossi or NPH is part of the horizontal gaze holding system. It functions as a neural integrator. A cross section of the lower pons showing the nucleus prepositus hypoglossi (#5) labeled at the… …   Wikipedia

  • magnus raphe nucleus — n. raphes magnus …   Medical dictionary

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”