Dorsal root ganglion
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2008-06-16T15:35:50Z
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/* Location */
{{Infobox Anatomy |
Name = {{PAGENAME}} |
Latin = g. sensorium nervi spinalis |
GraySubject = 185 |
GrayPage = 750 |
Image = DRG Chicken e7.jpg|thumb |
Caption = This is a dorsal root ganglion (DRG) from a chicken [[embryo]] (around stage of day 7) after incubation overnight in [[nerve growth factor|NGF growth medium]] stained with anti-[[neurofilament]] [[antibody]]. Axons growing out of the ganglion are visible. |
Image2 = Gray675.png |
Caption2 = A spinal nerve with its anterior and posterior roots. The dorsal root ganglion is the "spinal ganglion", following the posterior/dorsal root. |
Precursor = [[neural crest]] |
System = |
MeshName = Spinal+Ganglia |
MeshNumber = A08.340.390.340 |
DorlandsPre = g_02 |
DorlandsSuf = 12384883 |
}}
In [[anatomy]] and [[neurology]], the '''dorsal root [[ganglion]]''' (or '''spinal ganglion''') is a nodule on a [[dorsal root]] that contains cell bodies of [[neuron]]s in [[afferent nerve|afferent]] [[spinal nerve]]s.
==Unique unipolar structure==
The [[axons]] of dorsal root ganglion neurons are known as [[afferents]]. In the [[peripheral nervous system]], afferents refer to the axons that relay sensory information into the [[central nervous system]] and [[spinal cord]]. These neurons are of the [[pseudo-unipolar neuron|pseudo-unipolar]] type, meaning they have an axon with two branches that act as a single axon, often referred to as a ''distal process'' and a ''proximal process''.
Unlike the majority of neurons found in the [[central nervous system]], an [[action potential]] in dorsal root ganglion neuron may initiate in the ''distal process'' in the periphery, bypass the cell body, and continue to propagate along the ''proximal process'' until reaching the [[synaptic terminal]] in the dorsal horn of the spinal cord.
==Distal section==
The distal section of the axon may either be a bare nerve ending or encapsulated by a structure that helps relay specific information to nerve. For example, a [[Meissner's corpuscle]] or [[Pacinian corpuscle]] may encapsulate the nerve ending, rendering the ''distal process'' sensitive to mechanical stimulation, such as stroking or vibration, respectively. <ref>[[Eric R. Kandel|Kandel ER]], Schwartz JH, Jessell TM. ''[[Principles of Neural Science]]'', 4th ed., p.431-433. McGraw-Hill, New York (2000). ISBN 0-8385-7701-6</ref>
==Location==
The dorsal root ganglia lie along the vertebral column by the spine.
==Embryology==
The dorsal root ganglia develops in the embryo from [[neural crest]] cells.
==Nociception==
[[G protein-coupled receptor]] on the DRG have been associated with [[nociception]].<ref name="pmid17720533">{{cite journal |author=Huang CW, Tzeng JN, Chen YJ, Tsai WF, Chen CC, Sun WH |title=Nociceptors of dorsal root ganglion express proton-sensing G-protein-coupled receptors |journal=Mol. Cell. Neurosci. |volume=36 |issue=2 |pages=195–210 |year=2007 |pmid=17720533 |doi=10.1016/j.mcn.2007.06.010}}</ref>
==References==
{{reflist}}
==See also==
* [[Ventral root]]
==Additional images==
<gallery>
Image:Medulla spinalis - Section - English.svg|Medulla spinalis
Image:spinal nerve.svg |The formation of the spinal nerve from the dorsal and ventral roots |
Image:Gray799.svg|Scheme showing structure of a typical spinal nerve.
</gallery>
==External links==
* {{SUNYAnatomyFigs|02|04|09}}
* {{BUHistology|04401loa}}
* [http://www.mansfield.ohio-state.edu/~jbradley/SpinalModelA.html Photo of model] at [[Ohio State University]]
* [http://webanatomy.net/histology/neural/cord_ganglion.jpg Diagram] at webanatomy.net
* [http://bioweb.uwlax.edu/aplab/Table_of_Contents/Lab_06/Dorsal_Root_1/dorsal_root_1.html Photo] at uwlax.edu
{{Spinal cord}}
[[Category:Nervous system]]
[[Category:back anatomy]]
{{neuroscience-stub}}
[[es:Ganglio espinal]]
[[fr:Ganglion spinal]]
[[it:Ganglio dorsale]]
[[ja:後根神経節]]