Development of all-optical imaging system for studying cerebral blood flow regulation using optogenetics

摘要

We present all-optical imaging system for studying cerebral blood flow regulation. To investigate changes in blood flowin the brain, it is necessary to visualize the vascular microstructure between neurons, astrocytes, and vascular cells andmonitor changes in vessel diameter and blood flow velocity. Optogenetics is an excellent technology that can be appliedto cerebral blood flow regulation studies that require superior spatial and temporal resolution and individual control ofcellular activity. The developed optical system is a new integrated optical imaging system that can apply all of thetechniques mentioned above for cerebral blood flow regulation research. The optical system includes a dual-colorfluorescence imaging system and a laser stimulation system. The system successfully performed dual-color fluorescenceimaging with a 50 μm grid pattern in the two wavelength ranges of 515-545 nm and 608-631 nm. It also performed laserstimulation with a minimum output laser pattern size of 2 x 2 μm~2 and a maximum intensity of up to 120 mW/mm~2. Inaddition, the optical system measured the fast flow velocity of fluorescent microbeads up to 1.9 μm/ms. Experimentalresults show that the system can be a promising tool for cerebral blood flow regulation studies that require optogeneticstimulation and dual-fluorescence imaging while measuring blood flow velocity. In the future, the all-optical imagingsystem will be applied to fiber bundle-based endoscopic systems developed to study cerebral blood flow regulation usingoptogenetics in living animal brains.