Astrocytes: Glutamate transport and alternate splicing of transporters

Astrocytes are poly-functional cells that are present in all vertebrate central nervous systems. They exhibit diverse anatomical characteristics and functional properties, including playing a key role in the homeostasis of the excitatory neurotransmitter glutamate. Glutamate is rapidly removed from the extracellular space after the release of such by neurons, removal being mediated predominantly by astrocytes. Multiple glutamate- or “excitatory amino acid-transporters” exist, the predominant astrocytic types being EAAT1 and EAAT2. These transporters are subject to alternate splicing. This review considers key aspects of astrocyte biology including glutamate transport, the targeting of EAATs to specific membrane domains, and notes the way that activity may potentially drive alternate splicing as well as contributing to the precise anatomical compartmentation of the resultant EAATs. Such coordinate mechanisms may potentially contribute to changes in astrocyte function, especially in pathological contexts.