@misc{oai:repo.qst.go.jp:00070276,
 author = {Takuwa, Hiroyuki and Masamoto, Kazuto and Obata, Takayuki and Kanno, Iwao and 田桑 弘之 and 正本 和人 and 小畠 隆行 and 菅野 巖},
 month = {Oct},
 note = {Introduction: It was well known that chronic hypoxia caused morphological changes in microvascular architecture in the brain. We sought that astroglia which wrap cerebral microvessels play a key role in promoting angiogenesis and balancing metabolic demand during hypoxic adaptation. To this end, we performed time-volume imaging of microvascular architecture and astroglial networks in mouse cerebral cortex induced by chronic hypoxia. 
Materials and Methods: Male C57BL/6J mice anesthetized with isoflurane were used for the experiments. A custom-made attachment device was fixed on the skull, and craniotomy was performed over the somatosensory area. The animals were housed into hypoxic chamber in which ambient oxygen concentration was maintained at 10-11%. Longitudinal two-photon imaging (TCS SP5 MP, Leica Microsystems GmbH) excited at 900 nm (Titanium-sapphire laser , Mai Tai HP, Spectra-Physics) was repeatedly performed in the same location of the somatosensory barrel cortex from one day before the hypoxic exposure up to one month from onset of the hypoxic exposure. In each imaging session, microvascular and astroglial networks were preliminarily labeled with sulforhodamine 101 (SR 101, MP Biomedicals). Fluorescent glucose imaging (2-NBDG, Peptide Institute Inc.) was also performed. A single image plane consists of 1024 by 1024 pixels, and a volume image was acquired up to a depth of 0.8 mm from a cortical surface with a z-step size of 5 µm. After all imaging sessions were completed, the animal was allowed to wake up from anesthesia and back to hypoxic chamber. On a separate date, behavior performances and hemodynamic functions to whisker stimulation were concurrently recorded under normoxic conditions. Whisker stimulation (frequency 10 Hz and duration 20 sec) was given to the contra-lateral side of the measurement site, while behavior locomotion was quantified with optical motion sensor.
Results and Discussion: We observed that cerebrovenous vessels were drastically growing during three weeks of hypoxic exposure, while behavior performances and hemodynamic functions were relatively maintained. An increase in microvessel density and astroglial volume growth were also observed. In astroglia, the process approaching to the microvessel walls were significantly getting thick. The spatial correspondence between vessel growth and astroglial wrap were under investigated. The possible role of astroglia adaptation on remodeling of microvascular architecture induced by chronic hypoxia will be discussed., 第29回内藤コンファレンス},
 title = {Morphological adaptation of microvascular architecture and astroglia induced by chronic hypoxia in mouse cortex.},
 year = {2010}
}