Retinal glia

Retinal glial cells play key roles in retinal function. Both Müller cells and astrocytes, the two types of macroglial cells of the retina, have complex physiological properties. They express a wide variety of ion channels, receptors, and transporters. Prominent among these are inwardly rectifying K⁺ channels, purinergic receptors, and high-affinity glutamate transporters. Retinal glia contribute to many essential retinal functions, including regulating the retinal microenvironment by controlling extracellular glutamate and K⁺ levels, modulating neuronal activity by releasing gliotransmitters, regulating blood flow in response to changes in neuronal activity, and providing active metabolic support to retinal neurons. Retinal glia are integral and essential elements of the retina.