Grey matter

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)

---

Grey matter
The formation of the spinal nerve from the dorsal and ventral roots. (Gray matter labeled at center right.)
Latin	substantia grisea
Gray's	subject #
System
MeSH	[1]
File:Grey matter and white matter - very high mag.jpg
Micrograph showing grey matter, with the characteristic neuronal cell bodies (right of image - dark shade of pink), and white matter with its characteristic fine meshwork-like appearance (left of image - lighter shade of pink). HPS stain.

Grey matter (or gray matter) is a major component of the central nervous system, consisting of neuronal cell bodies, neuropil (dendrites and unmyelinated 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. 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.

Function

Grey matter is made up of neuronal cell bodies. The grey matter includes regions of the brain involved in muscle control, sensory perception such as seeing and hearing, memory, emotions, and speech.

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).

Research

Volume and cognition in elderly people

Significant positive correlations have been found between grey matter volume in elderly persons and measures of semantic and short-term memory. No significant correlations with white matter volume were found. These results suggest that individual variability in specific cognitive functions that are relatively well preserved with ageing is accounted for by the variability of gray matter volume in healthy elderly subjects.

Volume associated with bipolar disorder

Some structural differences in grey matter may be associated with psychiatric disorders. There was no difference in whole-brain grey matter volume between patients with bipolar I disorder and healthy controls. Subjects with bipolar I disorder had smaller volumes in the left inferior parietal lobule, right superior temporal gyrus, right middle frontal gyrus, and left caudate. Only the volume of the right middle frontal gyrus was correlated with duration of illness and the number of episodes in patients.

Effects of smoking

Older smokers lose grey matter and cognitive function at a greater rate than non-smokers. Chronic smokers who quit during the study lost fewer brain cells and retained better intellectual function than those who continued to smoke.

Effects of child abuse

Adolescents who were subjected to abuse and neglect appear to have decreased gray matter in the prefrontal cortex.

See also

• Gray matter heterotopia
• Neuropil
• Periaqueductal grey matter
• Rexed laminae
• Substantia nigra
• White matter

Additional images

Human brain right dissected lateral view description.JPG

Human brain right dissected lateral view

Schematic representation of the chief ganglionic categories (I to V).

External links

• Dictionary at eMedicine Gray+matter

|}

|}