Glial cells are cells that help maintain homeostasis, provide nutrition and supportm, form myelin and participate in signal transmission. When providing support for neurons the Glial cells are commenly referred to as "glue". They are necessary to keep the neuron system functioning properly. Unlike other neurons they do not conduct impulses rather regulate some parts of the nervous system(Bailey, 2007).

4 Main Functions (Wolosker, 2008)

1) Surrond and Hold neurons in place
2)Supply nutrients and oxygen
A Close Up Look Of Glial Cells
A Close Up Look Of Glial Cells

3)Insulate neurons
4)Remove Dead Neurons

In the brain glial cells outnumber the number of neurons greatley. Close to a 100 billion neurons are racing through our brain as we speak and glial cells multiply this by close to 10-50 times. (Jessen, 2005)

Types (Chudler, 2006)

Oligodendrocytes - Provide insulation to neurons in the CNS
Astrocytes - Star Shaped cells that provide physical and nutritional support
Microglia - Digest parts of dead neurons
Schwann Cells - Provide the insulation to neurons in PNS


external image gliacom.gif


References
1) Bailey, Regina. About.com/Biology. http://biology.about.com/od/anatomy/a/aa032808a.htm
2) FEBS J. 2008 Jul;275(14):3514-26.d- Amino acids in the brain: d-serine in neurotransmission and neurodegeneration. Wolosker H, Dumin E, Balan L, Foltyn VN. http://www.ncbi.nlm.nih.gov/pubmed/185641803)
3) Jessen, Kristjan. Encyclopedia of Science. http://www.iscid.org/encyclopedia/The_Glial_Cell
4) Chudler, Eric. Neuroscience for Kids. http://faculty.washington.edu/chudler/glia.html