Alzheimer type II 3975 astrocytes actively metabolize the excess blood ammonium present in liver failure. Following a cerebral infarct, astrocytes hypertrophy, proliferate, and form a glial scar around the necrotic area. They also produce neuronal growth factors. Astrocytes also induce certain enzymes, found only in the cerebral capillary endothelium, and produce a growth factor for cerebral capillaries. This may help prevent over-stimulation of neurons by leftover neurotransmitters.
Astrocytes also take up various extracellular ions.
They are found perineuronally and in the white matter. Functions Oligodendrocytes are the myelinating cells of the CNS, sending out a thin process to each myelinated axon. Oligodendrocytes may function in neuronal nutrition. Microglia Histology Microglia have small, elongated nuclei 3989 Functions Microglia are derived from the same bone marrow precursor cells that give rise to tissue macrophages. They are of mesodermal, rather than neuroectodermal origin, migrating into the CNS along with the fetal blood vessels.