| Gray matter |  | | The formation of the spinal nerve from the dorsal and ventral roots. (Grey matter labeled at center right.) |  | | Latin | substantia grisea | | Dorlands/Elsevier | Gray matter | Grey matter is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil (dendrites and both unmyelinated axons and myelinated axons), glial cells (astroglia and oligodendrocytes) and capillaries. Grey matter contains neural cell bodies, in contrast to white matter, which does not and mostly contains myelinated axon tracts.[1] The color difference arises mainly from the whiteness of myelin. In living tissue, grey matter actually has a grey-brown color which comes from capillary blood vessels and neuronal cell bodies. [edit] Distribution Grey matter is distributed at the surface of the cerebral hemispheres (cerebral cortex) and of the cerebellum (cerebellar cortex), as well as in the depths of the cerebrum (thalamus; hypothalamus; subthalamus, basal ganglia - putamen, globus pallidus, nucleus accumbens; septal nuclei), cerebellar (deep cerebellar nuclei - dentate nucleus, globose nucleus, emboliform nucleus, fastigial nucleus), brainstem (substantia nigra, red nucleus, olivary nuclei, cranial nerve nuclei) and spinal grey matter (anterior horn, lateral horn, posterior horn). [edit] Function The function of grey matter is to route sensory or motor stimulus to interneurons of the CNS in order to create a response to the stimulus through chemical synapse activity. Grey matter structures (cortex, deep nuclei) process information originating in the sensory organs or in other gray matter regions. This information is conveyed via specialized nerve cell extensions (long axons), which form the bulk of the cerebral, cerebellar, and spinal white matter. [edit] See also [edit] Additional images Human brain right dissected lateral view | Schematic representation of the chief ganglionic categories (I to V). | [edit] References - ^ Purves, Dale, George J. Augustine, David Fitzpatrick, William C. Hall, Anthony-Samuel LaMantia, James O. McNamara, and Leonard E. White (2008). Neuroscience. 4th ed.. Sinauer Associates. pp. 15-16. ISBN 978-0-87893-697-7.
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