The formation of the spinal nerve from the dorsal and ventral roots (with grey matter labelled at centre right).
Micrograph showing grey matter, with the characteristicneuronal cell bodies (dark shade of pink), andwhite matter with its characteristic fine meshwork-like appearance (left of image; lighter shade of pink).HPS stain.
Grey matter (gray matter inAmerican English) is a major component of thecentral nervous system, consisting ofneuronalcell bodies,neuropil (dendrites and unmyelinatedaxons),glial cells (astrocytes andoligodendrocytes),synapses, andcapillaries. Grey matter is distinguished fromwhite matter in that it contains numerous cell bodies and relatively few myelinated axons, while white matter contains relatively few cell bodies and is composed chiefly of long-range myelinated axons.[1] The colour difference arises mainly from the whiteness ofmyelin. In living tissue, grey matter actually has a very light grey colour with yellowish or pinkish hues, which come from capillary blood vessels and neuronal cell bodies.[2]
Cross-section of a spinalvertebra with the spinal cord in the centre (and grey matter labelled).
Cross-section ofspinal cord with the grey matter labelled.
Grey matter undergoes development and growth throughout childhood and adolescence.[3] Recent studies using cross-sectional neuroimaging have shown that by around the age of 8 the volume of grey matter begins to decrease.[4] However, the density of grey matter appears to increase as a child develops into early adulthood.[4] Males tend to exhibit grey matter of increased volume but lower density than that of females.[5]
Grey matter contains most of the brain's neuronal cell bodies.[6] The grey matter includes regions of the brain involved in muscle control, and sensory perception such as seeing and hearing, memory, emotions, speech, decision-making, and self-control.
The grey matter in thespinal cord is split into three grey columns:
The grey matter of the spinal cord can be divided into different layers, calledRexed laminae. These describe, in general, the purpose of the cells within the grey matter of the spinal cord at a particular location.
Interneurons present in the grey matter of the spinal cord
Rexed laminae groups the grey matter in the spinal cord according to its function.
Highalcohol consumption has been correlated with significant reductions in grey matter volume.[7][8] Short-termcannabis use (30 days) is not correlated with changes inwhite or grey matter.[9] However, several cross-sectional studies have shown that repeated long-term cannabis use is associated with smaller grey matter volumes in thehippocampus,amygdala, medialtemporal cortex, andprefrontal cortex, with increased grey matter volume in the cerebellum.[10][11][12] Long-term cannabis use is also associated with alterations in white matter integrity in an age-dependent manner,[13] with heavy cannabis use during adolescence and early adulthood associated with the greatest amount of change.[14]
Habitual playing of action video games has been reported to promote a reduction of grey matter in the hippocampus while 3D platformer games have been reported to increase grey matter in the hippocampus.[20][21][22]
Women and men with equivalent IQ scores have differing proportions of grey to white matter in cortical brain regions associated with intelligence.[23]
Pregnancy renders substantial changes in brain structure, primarily reductions in grey matter volume in regions subserving social cognition. Grey matter reductions endure for at least 2 years post-pregnancy.[24] The profile of brain changes is comparable to that taking place during adolescence, a hormonally similar transitional period of life.[25]
In the current edition[26] of the official Latin nomenclature,Terminologia Anatomica,substantia grisea is used for Englishgrey matter. The adjectivegrisea forgrey is however not attested inclassical Latin.[27] The adjectivegrisea is derived from theFrench word for grey,gris.[27] Alternative designations likesubstantia cana[28] andsubstantia cinerea[29] are being used alternatively. The adjectivecana, attested in classical Latin,[30] can meangrey,[27] orgreyish white.[31] The classical Latincinerea meansash-coloured.[30]
^Purves D, Augustine GJ, Fitzpatrick D, Hall WC, LaMantia AS, McNamara JO, White LE (2008).Neuroscience (4th ed.). Sinauer Associates. pp. 15–16.ISBN978-0-87893-697-7.
^Kolb B, Whishaw IQ (2003).Fundamentals of human neuropsychology (5th ed.). New York: Worth Publishing. p. 49.ISBN978-0-7167-5300-1.
^Miller AK, Alston RL, Corsellis JA (1980). "Variation with age in the volumes of grey and white matter in the cerebral hemispheres of man: measurements with an image analyser".Neuropathology and Applied Neurobiology.6 (2):119–32.doi:10.1111/j.1365-2990.1980.tb00283.x.PMID7374914.S2CID23201991.
^Yang X, Tian F, Zhang H, Zeng J, Chen T, Wang S, Jia Z, Gong Q (July 2016). "Cortical and subcortical gray matter shrinkage in alcohol-use disorders: a voxel-based meta-analysis".Neuroscience and Biobehavioral Reviews.66:92–103.doi:10.1016/j.neubiorev.2016.03.034.PMID27108216.S2CID19928689.
^Xiao P, Dai Z, Zhong J, Zhu Y, Shi H, Pan P (August 2015). "Regional gray matter deficits in alcohol dependence: A meta-analysis of voxel-based morphometry studies".Drug and Alcohol Dependence.153:22–8.doi:10.1016/j.drugalcdep.2015.05.030.PMID26072220.
^Lorenzetti V, Lubman DI, Whittle S, Solowij N, Yücel M (September 2010). "Structural MRI findings in long-term cannabis users: what do we know?".Substance Use & Misuse.45 (11):1787–808.doi:10.3109/10826084.2010.482443.PMID20590400.S2CID22127231.
^Matochik JA, Eldreth DA, Cadet JL, Bolla KI (January 2005). "Altered brain tissue composition in heavy marijuana users".Drug and Alcohol Dependence.77 (1):23–30.doi:10.1016/j.drugalcdep.2004.06.011.PMID15607838.
^Fox KC, Nijeboer S, Dixon ML, Floman JL, Ellamil M, Rumak SP, Sedlmeier P, Christoff K (June 2014). "Is meditation associated with altered brain structure? A systematic review and meta-analysis of morphometric neuroimaging in meditation practitioners".Neuroscience and Biobehavioral Reviews.43:48–73.doi:10.1016/j.neubiorev.2014.03.016.PMID24705269.S2CID207090878.
^Hoekzema E, Barba-Müller E, Pozzobon C, Picado M, Lucco F, García-García D, Soliva JC, Tobeña A, Desco M, Crone EA, Ballesteros A, Carmona S, Vilarroya O (February 2017). "Pregnancy leads to long-lasting changes in human brain structure".Nature Neuroscience.20 (2):287–296.doi:10.1038/nn.4458.hdl:1887/57549.PMID27991897.S2CID4113669.
^abcTriepel H (1910).Die anatomischen Namen. Ihre Ableitung und Aussprache. Mit einem Anhang: Biographische Notizen (3rd ed.). Wiesbaden: Verlag J.F. Bergmann.[page needed]
^Triepel H (1910).Nomina Anatomica. Mit Unterstützung von Fachphilologen. Wiesbaden: Verlag J.F. Bergmann.[page needed]
^Schreger CH (1805). "Synonymia anatomica. Synonymik der anatomischen Nomenclatur". In Fürth (ed.).Bureau für Literatur.[page needed]
^abLewis CT, Short C (1879).A Latin dictionary founded on Andrews' edition of Freund's Latin dictionary. Oxford: Clarendon Press.[page needed]
^Stearn WT (1983). Charles D (ed.).Botanical Latin. History, grammar, syntax, terminology and vocabulary (3rd ed.). London: Newton Abbot.[page needed]
