抄録
Flavoprotein autofluorescence signals are intimately coupled with neural activities, and are applicable for functional brain imaging. The transparent skull of mice allows trans-cranial autofluorescence imaging of cortical activities in mice. In this study, cortical plasticity induced by monocular deprivation in the mouse visual cortex was investigated with this technique. C57bl/6 mice were anaesthetized with urethane. An increase in autofluorescence in the visual cortex was elicited by light stimuli at the timing of ON- and OFF-responses. Field potential recordings were performed to confirm, whether underlying neural activities were reflected by the autofluorescence signals. Evoked potentials after light stimuli were observed inside but not outside the autofluorescence responsive area. Autofluorescence signals were about 10 times larger in amplitude and faster in timecourse than intrinsic signals, which have been widely used for functional brain imaging. Effects of monocular deprivation for 4 days in the critical period were evaluated a few weeks after the deprivation with autofluorescence imaging. Monocular deprivation selectively diminished the autofluorescence responses to light stimuli applied to the deprived eyes in the binocular zone but not in the monocular zone of the visual cortex. These results indicate that cortical plasticity induced by monocular deprivation can be investigated with trans-cranial autofluorescence imaging in the mouse visual cortex. [Jpn J Physiol 55 Suppl:S164 (2005)]
