@misc{oai:repo.qst.go.jp:00069783,
 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 = {Jul},
 note = {Background: There have been a number of studies concerning the mechanism regulating CBF induced by neuronal activity (neurovascular coupling) in animals. However, most studies were performed under the anesthetized condition. Since anesthesia greatly affects neurovascular coupling1 and systemic physiology (e.g., blood pressure, heart rate, etc.), the implications from the anesthetized animal studies may not be directly applicable to human fMRI studies that are usually performed on awake subjects in clinical and neuroscience research. In the present study, we therefore aimed to develop a novel model for neurovascular physiologic studies in awake-behaving mice. 
Material and Methods: This study was conducted in C57BL/6J mice (5-7 weeks). The regional CBF (rCBF) in the somatosensory cortex was continuously measured with laser-Doppler flowmetry (LDF), while the mice were fully awake. A metal head plate was attached to the skull and the mice were tethered by screwing the head plate onto a metal rod. Below the animals, a styrofoam ball supported by a jet of air was set in the apparatus. The styrofoam ball freely rotated while the mice walked on it. In order to record the walking velocity of the mice, an optical computer mouse was set so that movement of the ball could be detected. The behavior of the mice was video-recorded using a digital camera. The animal behavior, while being tethered (e.g. running, resting and grooming, etc) was later analyzed by displaying it on a CRT and comparison was made with LDF data recorded simultaneously. The dynamic LDF data were compared across the conditions of resting, running, grooming and whisker stimulation (stimulus frequency 10 Hz and duration 10 sec).
Results and Discussion: During the resting state, the spontaneous fluctuation (standard deviation) of the rCBF was 2.7% relative to the mean LDF. The baseline level of the LDF signal did not change significantly over 1.5 hours recording. The rCBF change was also stable (SD = 3.5%) when the animals were running. These results show that a motion artifact caused by running did not significantly affect the LDF measurements. The rCBF increased by about 20% during a period of spontaneous grooming. The rCBF change induced by whisker stimulation was observed to be about 29% of the baseline level at the peak intensity. 
In conclusion, the present awake-behaving mice model allows for the study of ongoing rCBF activity, and leads to better comparison with awake-behaving humans studied with fMRI noninvasively. 
References:
1 Kazuto Masamoto, Tae Kim, Mitsuhiro Fukuda, Ping Wang and Seong-Gi Kim, (2007) Relationship between Neural, Vascular, and BOLD Signals in Isoflurane-Anesthetized Rat Somatosensory Cortex: Cereb Cortex, 17(4), 942-950, XXIVth International Symposium on Cerebral Blood Flow, Metabolism and Function & VIth International Conference on Quantification of Brain Function with PET},
 title = {Dynamic recording of ongoing neurovascular activity in awake-behaving mice.},
 year = {2009}
}