Abstract: | Recent Ca2+ imaging studies in cell culture and in situ have shown that Ca2+ elevations in astrocytes stimulate glutamate release and increase neuronal Ca2+ levels, and that this astrocyte‐neuron signaling can be stimulated by prostaglandin E2 (PGE2). We investigated the electrophysiological consequences of the PGE2‐mediated astrocyte‐neuron signaling using whole‐cell recordings on cultured rat hippocampal cells. Focal application of PGE2 to astrocytes evoked a Ca2+ elevation in the stimulated cell by mobilizing internal Ca2+ stores, which further propagated as a Ca2+ wave to neighboring astrocytes. Whole‐cell recordings from neurons revealed that PGE2 evoked a slow inward current in neurons adjacent to astrocytes. This neuronal response required the presence of an astrocyte Ca2+ wave and was mediated through both N‐methyl‐D ‐aspartate (NMDA) and non‐NMDA glutamate receptors. Taken together with previous studies, these data demonstrate that PGE2‐evoked Ca2+ elevations in astrocyte cause the release of glutamate which activates neuronal ionotropic receptors. © 1999 John Wiley & Sons, Inc. J Neurobiol 41: 221–229, 1999 |