EAPSI: Synchronizing cell excitation and collection for deep-brain imaging

Heberle Dylan A, Ithaca NY

Investigators

Abstract

Optical imaging has had a tremendous impact on biological research and medical applications and procedures. Among the various imaging techniques, multiphoton fluorescence microscopy (MPM) has been used to image at significant depths within the brain. MPM uses a laser source to excite fluorescent molecules tagged to specific cells. When these molecules are excited, they emit light of a certain color that can be collected to produce an image. The goal of this research is to increase imaging speed and quality by synchronizing the excitation of the fluorescent molecules with the collection of the emitted light. By synchronizing the excitation and collection, the light is more efficiently collected, enabling faster imaging speed with better image quality. This project aims to build the synchronization system and will be conducted in collaboration with Dr. Tzu-Ming Liu at the National Taiwan University in Taiwan. Dr. Liu's group specializes in high-speed imaging and has developed and tested high-speed synchronization systems. Synchronizing the laser source and collection is advantageous for imaging deep within scattering materials such as brain. Currently, imaging depth is limited by the sample's thermal damage threshold, corresponding to a maximum allowable average power. For deeper imaging, the peak power must be increased. Now, to remain below the damage threshold, the repetition rate of the laser source must be decreased, reducing the imaging speed. With synchronization, only a few pulses per pixel (~5) are required to produce a clear image, compared to ~100 pulses per pixel without synchronization. With fewer pulses per pixel required to produce an image, this synchronization system will enable faster deep-brain imaging. This NSF EAPSI award is funded in collaboration with the National Science Council of Taiwan.