Editing Grey matter (section)

== Structure ==
Grey matter refers to unmyelinated [[neuron]]s and other cells of the [[central nervous system]]. It is present in the [[brain]], [[brainstem]] and [[cerebellum]], and present throughout the [[spinal cord]].

Grey matter is distributed at the surface of the [[cerebral hemisphere]]s ([[cerebral cortex]]) and of the cerebellum ([[cerebellar cortex]]), as well as in the depths of the cerebrum (the [[thalamus]]; [[hypothalamus]]; [[subthalamus]], [[basal ganglia]] – [[putamen]], [[globus pallidus]] and [[nucleus accumbens]]; as well as the [[septal nuclei]]), cerebellum (deep cerebellar nuclei – the [[dentate nucleus|dentate nuclei]], [[globose nucleus]], [[emboliform nucleus]], and [[fastigial nucleus]]), and [[brainstem]] (the [[substantia nigra]], [[red nucleus]], [[olivary body|olivary nuclei]], and [[cranial nerve nuclei]]).

Grey matter in the spinal cord is known as the [[grey column]] which travels down the spinal cord distributed in three grey columns that are presented in an "H" shape. The forward-facing column is the [[anterior grey column]], the rear-facing one is the [[posterior grey column]] and the interlinking one is the [[lateral grey column]]. The grey matter on the left and right side is connected by the [[gray commissure|grey commissure]]. The grey matter in the spinal cord consists of [[spinal interneuron|interneuron]]s, as well as the [[Soma (biology)|cell bodies]] of [[Projection fiber|projection neurons]].

<gallery>
File:Cervical_vertebra_english.png|Cross-section of a spinal [[vertebra]] with the spinal cord in the centre (and grey matter labelled).
File:Medulla spinalis - Section - English.svg|Cross-section of [[spinal cord]] with the grey matter labelled.
</gallery>

Grey matter undergoes development and growth throughout childhood and adolescence.<ref>{{cite journal | vauthors = Sowell ER, Thompson PM, Tessner KD, Toga AW | title = Mapping continued brain growth and gray matter density reduction in dorsal frontal cortex: Inverse relationships during postadolescent brain maturation | journal = The Journal of Neuroscience | volume = 21 | issue = 22 | pages = 8819–29 | date = November 2001 | pmid = 11698594 | pmc = 6762261 | doi = 10.1523/JNEUROSCI.21-22-08819.2001 }}</ref> Recent studies using cross-sectional neuroimaging have shown that by around the age of 8 the volume of grey matter begins to decrease.<ref name = "Gennatas_2017">{{cite journal | vauthors = Gennatas ED, Avants BB, Wolf DH, Satterthwaite TD, Ruparel K, Ciric R, Hakonarson H, Gur RE, Gur RC | title = Age-Related Effects and Sex Differences in Gray Matter Density, Volume, Mass, and Cortical Thickness from Childhood to Young Adulthood | journal = The Journal of Neuroscience | volume = 37 | issue = 20 | pages = 5065–5073 | date = May 2017 | pmid = 28432144 | pmc = 5444192 | doi = 10.1523/JNEUROSCI.3550-16.2017 }}</ref> However, the density of grey matter appears to increase as a child develops into early adulthood.<ref name = "Gennatas_2017" /> Males tend to exhibit grey matter of increased volume but lower density than that of females.<ref>{{cite journal |last1=Luders |first1=Eileen |last2=Gaser |first2=Christian |last3=Narr |first3=Katherine L. |last4=Toga |first4=Arthur W. |title=Why Sex Matters: Brain Size Independent Differences in Gray Matter Distributions between Men and Women |journal=The Journal of Neuroscience |date=11 November 2009 |volume=29 |issue=45 |pages=14265–14270 |doi=10.1523/JNEUROSCI.2261-09.2009 |pmid=19906974 |pmc=3110817 }}</ref>