Teaching resources. Glial intercellular waves.
Glial cells have long been assigned a supporting role in the nervous system, in which they help maintain and modulate neuronal metabolism. However, recent attention has focused on the ability of astrocytes to propagate long-range calcium signals and actively communicate with each other, as well as with neurons and vascular cells. Synaptic activity in neurons triggers an increase in the intracellular calcium concentration ([Ca2+]i) of neighboring astrocytes, stimulating the release of ATP and glutamate. The released ATP stimulates an increase in [Ca2+]i in neighboring astrocytes so that a "calcium wave" is propagated from cell to cell. Released glutamate is cotransported with Na+ into neighboring cells; thus, glutamate uptake leads to an increase in astrocyte intracellular sodium concentration ([Na+]i) that is also propagated from cell to cell. This increase in [Na+]i stimulates an increase in glucose uptake and metabolism that leads to the formation of lactate, which is delivered to nearby--and perhaps distant--neurons as an energy substrate. Thus, long-range intercellular calcium signaling in astrocytes may enable them to spatially coordinate their function in supporting neuronal metabolism.
Department of Neurology, David Geffen School of Medicine, UCLA, 710 Westwood Plaza, Los Angeles, CA 90095, USA. acharles@ucla.edu
Andrew
A
Charles
D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D001253:Astrocytes / Q000502:physiology*; D001695:Biology / Q000193:education*; D020013:Calcium Signaling / Q000502:physiology*; D002450:Cell Communication; D018698:Glutamic Acid / Q000378:metabolism; D009040:Motion Pictures; D012964:Sodium / Q000502:physiology*; D009435:Synaptic Transmission
D018698:Glutamic Acid; D000255:Adenosine Triphosphate; D012964:Sodium