Brain implants for wireless photometry and optogenetics

Abstract

Photometry and optogenetics are representative techniques for each optical neural recording and neuromodulation. Both have been powerful tools for studying complex networks of neurons owing to their cell-type specificity and high spatiotemporal resolution. Conventional methods depend on a fiber to deliver and collect optical signals, imposing limits including impediments to the natural behaviors of subjects and a requirement of complex external systems. Using a wireless brain implant integrated with microscale optoelectronics has removed such restraints, allowing separate wireless photometry or optogenetics. Still, current brain implants for wireless photometry employ an absorber-based optical notch filter and are unable to combine with optogenetics of different wavelengths. Here, a brain implant based on an optical bandpass filter simultaneously utilizing different wavelengths to implement wireless photometry and optogenetics is presented. The brain implant comprises a thin probe integrated with microscale optoelectronics, a transferable and narrow bandpass optical filter, and a module for wireless communication. Without external equipment, the brain implant successfully conducts wireless photometry and optogenetics of different wavelengths.