The Regulation of Glutamate-Induced Astrocytic [Ca^2 +]i Responses by the Desensitization of Metabotropic Glutamate Receptor

Abstract

Astrocyte (AS) has metabotropic glutamate receptor type 5 (mGluR5) and forms tripartite synapse with neurons. AS is thought to receive the information from neurons and to play an important role of information processing in the CNS. In hippocampal cultured AS, the application of glutamate induces the four patterns of astrocytic Ca^2 + responses. They were a sustained oscillation, a damped oscillation and a step-rise response. The astrocytes have the varieties of the intracellular Ca^2 + responses. Why does the variety come from? In the present study, we propose the desensitization process of mGluR5 causes the varieties of the astrocytic responses.