Abstract
In vivo visualization of neural circuits located in the deep brain area with a micro-endoscope
Recent advance in molecular biology enabled us to label specific sets of neurons with several fluorescence proteins. To visualize these labeled cells in vivo, we developed a micro-endoscope system which can be inserted into the brain and can provide circuit images with cellular resolution. The micro-endoscope was made from a commercially available image fiber in which three to six thousand optical fibers are bundled. For functional imaging of neurons, we combined this endoscope with a custom-built confocal laser scanner fitted with a high-speed resonance galvomotor, and obtained confocal endoscopic images at a frame rate of 18-100 fps depending on the number of vertical lines. Our endoscope system visualized fluorescence labeled individual neuron, Ca response in vivo and provided stable images of the neural circuits even in head-restricted alert mice.
