Astrocytes in glutamate neurotransmission.

Astrocytes maintain ionic, amino acid neurotransmitter, and water homeostasis in the extracellular space of the brain. The anatomy of the cells, with their network formation and their capacity to react to and produce humoral and long-distance, slow-speed transfer of information within the syncytium, makes them appear to be a class of cells able to produce integrated responses to multiple stimuli. Impairment of the control by astroglia over the extracellular milieu, e.g., glutamate (Glu) concentration, could lead to disturbances in the neuronal excitability. In this paper we summarize recent evidence of the effects of Glu interactions with astrocytes, i.e., monoamine receptor-mediated regulation of Glu carriers, Glu receptor influences on different ion-channels, and astroglial cell volume.