"Optogenetic Monitoring and Control of Electrical Spikes in E. Coli"
Adam Cohen
Depts. of Chemistry and Chemical Biology and of Physics
Harvard University
Abstract: To probe neural function, one would like to monitor the simultaneous electrical activity in a large number of neurons, with high resolution in space and time. Genetically encoded optical indicators of membrane potential are a promising approach to this challenge. But thus far these molecules have lacked adequate sensitivity and speed.
We developed a voltage indicator based on a mutant of green proteorhodopsin. In the wild, bacteria use this light-driven proton pump to convert sunlight into electrochemical energy. We engineered the protein to run backward: to convert changes in membrane potential into a measureable optical signal. Bacteria expressing this protein show periodic flashes of fluorescence, indicating spontaneous electrical spiking. I will discuss possible mechanisms and biological significance for this spiking behavior.
Location: Joseph Henry Room
Date/Time: 10/11/10 at 11:45 am - 10/11/10 at 1:00 pm
Category: Biophysics Seminar
Department: Physics