This image shows two important support cells (glial cells) of the human brain. The green splash is a microglial cell, which responds to immune reactions in the central nervous system. <br /><br />Microglial cells recognize areas of damage and inflammation and swallow cellular debris. The larger orange shape is an oligodendrocyte. The ragged extensions of an oligodendrocyte can supply many neurons (nerve cells) with myelin, an insulating material which allows each neuron's communicating axon to transmit electrical impulses efficiently.