Miniature voltage sensitive dye imaging system for in vivo experiments

Abstract

Currently, there are no widely used methods of optically recording rapid electrical events over a wide cortical area in freely moving animals. This paper presents an image sensor for recording electrical activity of large regions (4–9 mm2) of the nervous tissue at high speeds (≫ 500 Hz) using voltage sensitive dye imaging (VSDI) in freely moving animals. Each 75 μm x 75 μm pixel consists of a photodiode of 74 μm x 34 μm and a storage capacitor of 788 fF. The image sensor has a signal-to-noise ratio of 76 dB.