Speaker: Adam Bowman, Principal Investigator at Salk, Institute for Biological Studies

Time: 13:00-14:00 p.m., Jun 26, 2025, GMT+8

Venue: Youcai Deng Hall, Jinguang Life Sciences building, PKU 

Abstract: 

Fluorescence lifetime imaging holds great promise for achieving quantitative measurements of fluorescent sensors in the brain. We present recent progress developing fast, all-optical methods to image fluorescence lifetime in vivo. Electro-optic fluorescence lifetime imaging (EO-FLIM) uses optical modulators to gate images onto standard scientific cameras, allowing lifetime estimation at every image pixel in parallel with high photon throughput. We demonstrate that EO-FLIM may be applied to wide-field imaging of a genetically encoded voltage indicator expressed in Drosophila neurons in vivo, achieving kilohertz frame rates and less than 5 picosecond lifetime resolution. Action potentials and sub-threshold voltage features are studied in lifetime and are mapped throughout neuronal structures. Standard techniques rely on measuring AF/F to quantify neuron activity. FLIM instead allows measurement of an absolute change in fluorescence lifetime without normalizing to a moving average baseline. Since EO-FLIM measures a ratio of image intensities, it also provides significant improvements in signal-to-noise ratio and can reiect technical noise and motion artifacts. We also present the next steps in EO-FLIM technology development along with the achievable performance for lifetime estimation and multi-exponential unmixing.

Source: Center for Life Sciences, PKU