Intercellular signaling in glial cells: Calcium waves and oscillations in response to mechanical stimulation and glutamate

Abstract

Intercellular Ca 2+ signaling in primary cultures of glial cells was investigated with digital fluorescence video imaging. Mechanical stimulation of a single cell induced a wave of increased [Ca 2+] i that was communicated to surrounding cells. This was followed by asynchronous Ca 2+ oscillations in some cells. Similar communicated Ca 2+ responses occurred in the absence of extracellular Ca 2+, despite an initial decrease in [Ca 2+] i in the stimulated cell. Mechanical stimulation in the presence of glutamate induced a typical communicated Ca 2+ wave through cells undergoing asynchronous Ca 2+ oscillations in response to glutamate. The coexistence of communicated Ca 2+ waves and asynchronous Ca 2+ oscillations suggests distinct mechanisms for intra- and intercellular Ca 2+ signaling. This intercellular signaling may coordinate cooperative glial function.