Label-free optophysiology of neural activity using dual-channel fast autofluorescence lifetime imaging microscopy (Conference Presentation)

Abstract

Active neurons experience rapid changes in their metabolic states since they have dynamic energy requirements. In this presentation, we demonstrate fast dual-channel label-free fluorescence lifetime imaging microscopy (FLIM) of NAD(P)H and FAD as a method for neurophysiology by performing computational photon counting in the onboard FPGA of the digitizer. The data throughput is reduced by 4x for each channel by compressing the photocurrents (16 bits) to photon counts (4 bits); the parallel processing on the FPGA ensures no lag. The setup was demonstrated for mammalian stem-cell-derived neurons under chemical stimulation, ion-channel blockers, and optical excitation. Fast FLIM on the FPGA enables dual-channel label-free metabolic optophysiology of neural activity in real time.