Gray matter astrocytes

Morgello S, Uson RR, Schwartz EJ, Haber RS (1995) The human blood-brain barrier glucose transporter (GLUTl) is a glucose transporter of gray matter astrocytes. Glia 14 43-54. 

Catalase and glutathione peroxidase provide two important cellular systems for eliminating H202. Catalase, a 56kDa cytosolic hemoprotein homotetramer that can act without a cofactor, although it may bind NAD(P)H, functions as a peroxidase to convert H202 to water. It can be irreversibly inactivated by oxidation and demonstrates decreased activity after ischemia-reperfusion. Catalase is more abundant in astrocytes than in neurons and in white matter than in gray matter, but it can be induced in neurons by neurotrophins. There is substantially less catalase activity in brain than in other tissues, such as liver. 

Macroglial cells are of ectodermal origin and include the astrocytes, ependymal cells, oligodendrocytes, and Schwann cells. Astrocytes appear to be primarily supportive in function and under microscopic examination can be seen to envelope axons and dendrites and buttress against the adventitial layer of blood vessels. In the gray matter of brain, which is composed primarily of perikarya, they have a clear protoplasmic appearance, whereas in the white matter, which is composed primarily of neuronal processes, they appear fibrous. Ependymal cells line the ventricles of the brain, are ciliated. 

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