Short pulses (ms to ms) of infrared light (1400-2100 nm) can excite action potentials in neurons; however, the mechanism driving this phenomenon is unknown. We are currently testing the hypothesis that infrared light alters the metabolic or redox balance of a cell. In support of our hypothesis, we have developed a model of infrared light and thermal dynamics on cell metabolism and enzyme binding properties. We are also using fluorescence lifetime imaging to reveal insights into infrared light effects enzyme binding dynamics and fast, wide-field fluorescence imaging to evaluate infrared light effects on cellular metabolism.