@article{oai:repo.qst.go.jp:00044919,
 author = {Maeda, Jun and Higuchi, Makoto and Inaji, Motoki and Ji, Bin and Haneda, Eisuke and Okauchi, Takashi and Zhang, Ming-Rong and Suzuki, Kazutoshi and Suhara, Tetsuya and 前田 純 and 樋口 真人 and 稲次 基希 and 季 斌 and 羽田 栄輔 and 岡内 隆 and 張 明栄 and 鈴木 和年 and 須原 哲也},
 journal = {Brain Research},
 month = {Jul},
 note = {Elevated levels of peripheral benzodiazepine receptor (PBR) in glia have been documented in diverse nervous system injuries, while the identity and spatiotemporal characteristics of the cells showing upregulation of PBR remain elusive. We examined the astrocytic and microglial expressions of PBR in rat brains during the duration of ethanol-induced neuronal insults in order to clarify the significance of PBR as a biomarker capable of detecting a distinctive subpopulation of these glial cells involved in the impairment and protection of neurons. The levels of PBR, as determined by autoradiographic analysis using a specific radioligand, [11C]DAA1106, began to significantly increase at 3 days after intrastriatal injection of ethanol, and peaked at 7 days. This was consistent with the results of double immunofluorescence staining and high-resolution emulsion autoradiography, which revealed upregulation of PBR in both microglia and astrocytes proliferating in nonoverlapping compartments of the injury site. Notably, increased expression of PBR in astrocytes was transiently observed in a manner parallel to the centripetal migration of these cells to the inflammatory lesion, which may be a response indispensable to the protection of intact tissue. Thereafter, astrocytic PBR was barely detectable, despite the presence of numerous glial fibrillary acidic protein-immunoreactive astrocytes forming glial scarring. By contrast, intense PBR signals were persistently present in microglia localized to the injury epicenter up to 90 days, notwithstanding a gradual reduction in the number of ionized calcium binding adapter molecule-1-positive amoeboid microglia between 7 and 90 days. The long-lasting PBR expression in microglia was finally supported by in vivo positron emission tomography imaging, and suggests that inflammatory tissue damage is potentially expandable unless it is tightly sealed by astrocytic scar. The present findings collectively support the utility of PBR in identifying a unique temporal pattern of astrocytic and microglial activation that conventional glial markers hardly pursue.},
 pages = {100--111},
 title = {Phase-dependent roles of reactive microglia and astrocytes in nervous system injury as delineated by imaging of peripheral benzodiazepine receptor},
 volume = {1157},
 year = {2007}
}