gray matter

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1. physical material having form and weight under ordinary conditions; called also substance.
2. pus.
gray matter areas of the nervous system where the nerve fibers are unmyelinated (not enveloped by a myelin sheath); it contains the bodies of the nerve cells. Tissue composed of myelinated fibers is called white matter. The cerebral cortex is entirely composed of gray matter and the cerebellum also contains some deep-seated masses of it. The spinal cord has a central core of gray matter surrounded by white matter; in cross section, its gray matter is shaped approximately like the letter H. Called also substantia grisea and gray substance.
white matter areas of the nervous system composed mostly of myelinated nerve fibers (those having myelin sheaths) constituting the conducting portion of the brain and spinal cord. Tissue composed of unmyelinated fibers is called gray matter. Called also substantia alba and white substance.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

gray mat·'ter

those regions of the brain and spinal cord that are made up primarily of the cell bodies and dendrites of nerve cells rather than myelinated axons.
Farlex Partner Medical Dictionary © Farlex 2012

gray matter

1. Brownish-gray nerve tissue, especially of the brain and spinal cord, composed of nerve cell bodies and their dendrites and some supportive tissue.
2. Informal Brains; intellect.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
Nonmyelinated cells and circuitry that comprise the ‘central processing unit’ of the CNS and spinal cord; the thinking part of the brain, which is composed of neuronal cell bodies, initial axon segments, dendritic processes, and arborizations, glia—neuroglial cells—capillaries and vascular support; gray matter is so named because it appears grayish; brain gray matter is peripheral; spinal cord gray matter is central
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

gray mat·ter

(grā mat'ĕr) [TA]
Those regions of the brain and spinal cord that are made up primarily of the cell bodies and dendrites of nerve cells rather than myelinated axons.
Synonym(s): substantia grisea [TA] , gray substance.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
Cortical gray matter and subcortical white matter brain microstructural changes in schizophrenia are localized and age independent: a case-control diffusion tensor imaging study.
Association of frontal and posterior cortical gray matter volume with time to alcohol relapse: A prospective study.
OCD patients showed, when compared with NCC, a significant decrease in gray matter volume of the left superior parietal lobe t(28)= 3.96, p<.0001 contrasting with a significant increase of gray matter in the right middle frontal gyrus t (28)= 4.14, p<.0001.
Statistical maps of local gray matter changes revealed the earliest decline occurring in basal ganglia, left olfactory, right precuneus, and left middle temporal gyrus.
To our knowledge, the present study is the first MRI study to compare gray matter volumes in female drug-naive depression patients who did or did not experience SLEs before the onset of depression.
Figure 1 presents the scatter plots depicting the correlation of left middle orbital gray matter volume and Trails B response time (r = -0.608, p < 0.003) and the correlation of right middle orbital gray matter volume and full-scale IQ (r = 0.610, p < 0.002).
In Section 3, a modified brain segmentation algorithm is proposed for gray matter extraction.
This review focuses on imaging gray matter pathology in MS and addresses the relationship between measures of gray matter pathology and the clinical and cognitive status of MS patients.
"This study demonstrates that our neural stem cells can induce regeneration of injured spinal cord axons into the graft and serve as a bridge to reconnect to gray matter motor neurons for many spinal cord segments below the injury," said Karl Johe, Ph.D., chief scientific officer.
The thickness of gray matter in the amygdala was also linked to the number of real-world friends people had, but the size of the other three regions appeared to be correlated only to online connections.
With more work on the hideous control set-up and more attention to detail, Gray Matter could have been great.
Gray matter is a reddish-brown layer that forms the cortex of the cerebrum and cerebellum.