Monday, July 9, 2012
Glial Cells and Your Brain
Ever heard of glial cells? Your brain has lots of them. As their name implies (Latin and\or Greek for glue), they help keep things together. Questions abound regarding the ratio of glial cells to neurons. Some say a 9:1 ratio; others that 80% are glias. Neurophysiologist Suzana Herculano-Houzel and colleagues have developed a new technique for estimating numbers of glial cells. An interesting finding is that rather than an overall constant glia-neuron ratio, the numbers change in different parts of the brain (e.g., there are much higher numbers of glial cells in the cerebral cortex as compared to the cerebellum). Regardless of the true glia to neuron ratio, scientists have already shown that glia are, functionally, the brain’s other half: some watch for bacteria and viruses that infect the brain and then mobilize to fight the invaders, others form myelin insulation to coat neuronal axons, while still others secrete food for neurons. They are indispensible!