title: Subcellular calcium dynamics during juvenile development in mouse hippocampal astrocytes.
abstract: Astrocytes generate calcium signals throughout their fine processes, which are assumed to locally regulate neighbouring neurotransmission and blood flow. The intercellular morphological relationships mature during juvenile periods when astrocytes elongate highly ramified processes. In this study, we examined developmental changes in calcium activity patterns of single hippocampal astrocytes using a transgenic mouse line in which astrocytes selectively express a genetically encoded calcium indicator, Yellow Cameleon-Nano50. Compared with postnatal day 7, astrocytes at postnatal day 30 showed larger subcellular calcium events and a greater proportion of somatic events. At both ages, the calcium activity was abolished by removal of extracellular calcium ions. Calcium events in late juvenile astrocytes were not affected by spontaneously occurring sharp waves that trigger synchronized neuronal spikes, implying the independence of astrocyte calcium signals from neuronal synchronization. These results demonstrate that astrocytes undergo dynamic changes in their activity patterns during juvenile development.
authors.affiliation: Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Nakayama
authors.affiliation: Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan.
authors.forename: Takuya
authors.initials: T
authors.lastname: Sasaki
authors.affiliation: Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Kenji F
authors.initials: KF
authors.lastname: Tanaka
authors.affiliation: Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan.|Center for Information and Neural Networks, Osaka, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ikegaya
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D020013:Calcium Signaling; D005110:Extracellular Space / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D051379:Mice
keywords: astrocyte; calcium; hippocampus; imaging