マツウラ　トオル   MATSUURA TORU   松浦　徹    所属   関西医科大学  病理学講座    職種   講師
論文種別	原著(症例報告除く)
言語種別	英語
査読の有無	査読あり
表題	Receptor-selective diffusion barrier enhances sensitivity of astrocytic processes to metabotropic glutamate receptor stimulation
掲載誌名	正式名：Science Signaling 略　 称：Sci Signal ISSNコード：19379145
掲載区分	国外
巻・号・頁	5(218),pp.ra27
著者・共著者	Misa Arizono, Hiroko Bannai, Kyoko Nakamura, Fumihiro Niwa, Masahiro Enomoto, Toru Matsu-ura, Akitoshi Miyamoto, Mark. W Sharwood, Takeshi Nakamura, Katsuhiko Mikoshiba
発行年月	2012/04
概要	Metabotropic glutamate receptor (mGluR)-dependent calcium ion (Ca²+) signaling in astrocytic processes regulates synaptic transmission and local blood flow essential for brain function. However, because of difficulties in imaging astrocytic processes, the subcellular spatial organization of mGluR-dependent Ca²+ signaling is not well characterized and its regulatory mechanism remains unclear. Using genetically encoded Ca²+ indicators, we showed that despite global stimulation by an mGluR agonist, astrocyte processes intrinsically exhibited a marked enrichment of Ca²+ responses. Immunocytochemistry indicated that these polarized Ca²+ responses could be attributed to increased density of surface mGluR5 on processes relative to the soma. Single-particle tracking of surface mGluR5 dynamics revealed a membrane barrier that blocked the movement of mGluR5 between the processes and the soma. Overexpression of mGluR or expression of its carboxyl terminus enabled diffusion of mGluR5 between the soma and the processes, disrupting the polarization of mGluR5 and of mGluR-dependent Ca²+ signaling. Together, our results demonstrate an mGluR5-selective diffusion barrier between processes and soma that compartmentalized mGluR Ca²+ signaling in astrocytes and may allow control of synaptic and vascular activity in specific subcellular domains.