nucleus raphe magnus

Information about nucleus raphe magnus

Brain:
Section of the medulla oblongata at about the middle of the olive. (Raphe nuclei not labeled, but 'raphe' labeled at left.)
Latinnucleus raphes magnus
NeuroNameshier-736
Dorlands/Elsevier n_11/12582800
The nucleus raphe magnus, located directly rostral to the raphe obscurus, is afferently stimulated from axons in the spinal cord and cerebellum.

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 [1].

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.

The periaquiductal gray, the epicenter of analgesia, sends efferent connections to the nucleus raphe 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 n.r. magnus.

The antinociceptic affects of electrical stimulation of the PAG can be blocked by administering naloxone, an opiate antagonist, to the 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.

See also

References

1. ^ 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


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Brain: rhombencephalon (hindbrain)
Myelencephalon/medulla
anterior/ventral: Arcuate nucleus of medulla • Pyramid (Decussation) • Olivary body • Inferior olivary nucleus • Anterior median fissure • Ventral respiratory group posterior/dorsal: VII,IX,X: Solitary/tract • XII, X: Dorsal • IX,X,XI: Ambiguus • IX: Inferior salivatory nucleus • Gracile nucleus/Cuneate nucleus/Accessory cuneate nucleus • Area postrema • Posterior median sulcus • Dorsal respiratory group raphe/reticular: Sensory decussation • Reticular formation (Gigantocellular nucleus, Parvocellular reticular nucleus, Ventral reticular nucleus, Lateral reticular nucleus, Paramedian reticular nucleus) • Raphe nuclei (Obscurus, Magnus, Pallidus) tracts: Corticospinal tract (Lateral, Anterior) • Inferior cerebellar peduncle • Olivocerebellar tract • Spinocerebellar (Dorsal, Ventral) • Spinothalamic tract • PCML (Posterior external arcuate fibers, Internal arcuate fibers, Medial lemniscus) • Extrapyramidal (Rubrospinal tract, Vestibulospinal tract, Tectospinal tract)
Metencephalon/pons
Metencephalon/cerebellumVermis • Flocculus • Arbor vitae • Cerebellar tonsil • Inferior medullary velum
Molecular layer (Stellate cell, Basket cell, Parallel fiber) • Purkinje cell layer (Purkinje cell) • Granule cell layer (Golgi cell) • Mossy fibers • Climbing fiber
Deep cerebellar nuclei (Dentate, Emboliform, Globose, Fastigial)
Fourth ventricleapertures (Median, Lateral) • Rhomboid fossa (Vagal trigone, Hypoglossal trigone, Obex, Sulcus limitans, Facial colliculus, Medial eminence) • Lateral recess
Latin}}} 
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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NeuroNames is a system of nomenclature for the human and/or macaque brain.

It is maintained by the University of Washington and is a part of a tool called "BrainInfo". BrainInfo helps one identify structures in the brain.
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Elsevier, the world's largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. Based in Amsterdam, the company has substantial operations in the UK, USA and elsewhere.
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The nucleus raphe obscurus, despite the implications of its name, has some very specific functions and connections of afferent and efferent nature. The raphe obscurus projects to the cerebellar lobes VI and VII and to crus II along with the nucleus raphe pontis [1].
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spinal chord is a thin, tubular bundle of nerves that is an extension of the central nervous system from the brain and is enclosed in and protected by the bony vertebral column.
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The cerebellum (Latin: "little brain") is a region of the brain that plays an important role in the integration of sensory perception and motor output. Many neural pathways link the cerebellum with the motor cortex—which sends information to the muscles causing them
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MUSCLE (multiple sequence comparison by log-expectation) is public domain, multiple sequence alignment software for protein and nucleotide sequences.
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Periaqueductal gray (PAG; also called the "central gray") is the midbrain grey matter that is located around the cerebral aqueduct within the midbrain. It plays a role in the descending modulation of pain and in defensive behaviour.
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The paraventricular nucleus (PVN) is an aggregation of neurons in the hypothalamus, which produces many hormones.

Location

It is adjacent to the third ventricle (hence the name of the nucleus.
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amygdalae (Latin, also corpus amygdaloideum, singular amygdala, from Greek
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The hypothalamus links the nervous system to the endocrine system via the pituitary gland (hypophysis). The hypothalamus, (from Greek ὑποθαλαμος = under the thalamus) is located below the thalamus, just above the brain stem.
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The parvocellular reticular nucleus is located dorsolateral to the nucleus reticularis pontis caudalis.

The dorsal portion of the reticular nucleus has been shown to innervate the mesencephalic trigeminal nucleus and its surrounding area.
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Periaqueductal gray (PAG; also called the "central gray") is the midbrain grey matter that is located around the cerebral aqueduct within the midbrain. It plays a role in the descending modulation of pain and in defensive behaviour.
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An analgesic (colloquially known as a painkiller) is any member of the diverse group of drugs used to relieve pain (achieve analgesia). The word analgesic derives from Greek an- ("without") and -algia ("pain").
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An analgesic (colloquially known as a painkiller) is any member of the diverse group of drugs used to relieve pain (achieve analgesia). The word analgesic derives from Greek an- ("without") and -algia ("pain").
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A nociceptor is a sensory receptor that sends signals that cause the perception of pain in response to potentially damaging stimulus. Nociceptors are the nerve endings responsible for nociception, one of the two types of persistent pain (the other, neuropathic pain, occurs when
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Naloxone is a drug used to counter the effects of opioid overdose, for example heroin or morphine overdose. Naloxone is specifically used to counteract life-threatening depression of the central nervous system and respiratory system.
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In literature, the antagonist is that against which the main character or protagonist contends. [1] An antagonist is often a Villain, but may be a force of nature, set of circumstances, an animal, or other force that is in conflict with the protaganist.
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The raphe nuclei (Latin for 'the bit in a fold or seam') is a moderate-size cluster of nuclei found in the brain stem, and releases serotonin to the rest of the brain.[1]
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In animals, the brain or encephalon (Greek for "in the skull"), is the control center of the central nervous system, responsible for behavior. The brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing,
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The rhombencephalon (or hindbrain) is a developmental categorization of portions of the central nervous system in vertebrates.

The rhombencephalon can be subdivided in a variable number of transversal swellings called rhombomeres.
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The myelencephalon is a developmental categorization of a portion of the central nervous system. The myelencephalon is composed of the medulla oblongata; contains a portion of the fourth ventricle; as well as the glossopharyngeal nerve (CN IX), vagus nerve (CN X), accessory nerve
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The medulla oblongata is the lower portion of the brainstem.

Location

By anatomical terms of location, it is rostral to the spinal cord and caudal to the pons, which is in turn ventral to the cerebellum.
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arcuate nucleus is a group of neurons located on the anterior surface of the medullary pyramids. They receive fibers from the corticospinal tract and send their axons through the external arcuate fibers and striae medullares to the cerebellum via the inferior cerebellar peduncle.
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The interior district of the medulla oblongata is named the pyramid and lies between the anterior median fissure and the antero-lateral sulcus.

Its upper end is slightly constricted, and between it and the pons the fibers of the abducent nerve emerge; a little below the
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pyramidal decussation.

Having crossed the middle line, they pass down in the posterior part of the lateral funiculus as the lateral cerebrospinal fasciculus.

Additional images



Diagrams of the medulla spinalis.

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In anatomy, the olivary bodies or simply olives (Latin oliva and olivae, singular and plural, respectively) are a pair of prominent oval structures in the medulla oblongata, the lower portion of the brainstem. They contain the olivary nuclei.
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The inferior olivary nucleus is the largest nucleus situated in the olivary body, part of the medulla oblongata.

It consists of a gray folded lamina arranged in the form of an incomplete capsule, opening medially by an aperture called the hilum.
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The anterior median fissure (ventral or ventromedian fissure) contains a fold of pia mater, and extends along the entire length of the medulla oblongata: it ends at the lower border of the pons in a small triangular expansion, termed the foramen cecum.
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The ventral respiratory group (VRG) is a column of neurons located in the ventrolateral region of the medulla, extending from the caudal facial nucleus to -400μm obex.
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