Transporter Proteins in Neurons and Glia

Glutamate is the brain's main excitatory neurotransmitter. Upon release, its actions are terminated by a class of proteins called glutamate transporters, which are located on the plasma membranes of neurons and glial cells. Glutamate transporters catalyze the movement of glutamate from the extracellular space to the intracellular space and are able to concentrate glutamate to greater than a millionfold under physiological circumstances by extracting energy from the sodium and potassium ionic gradients. This article discusses what is known about the molecular structure and function, the cellular localization, and the synaptic function of these critical components of excitatory synapses.