Aug.25th, Harvard University Prof. Adam Cohen Talk Annoucement


Leica Scientific Forum:

Title of the lecture: Bringing Bioelectric Phenomena to Light

Speaker: Professor Adam Cohen

               Professor of Chemistry and Chemical Biology and Physics,

               Harvard University,HHMI investigator

Time: 14:15 PM, Aug. 25th

Location: Lecture Hall A 204, College of Chemistry, Peking Univesity


Brief abstract of the lecture

In the wild, microbial rhodopsin proteins convert solar energy into a transmembrane voltage, which provides energy for their host.We engineered microbial rhodopsins to run in reverse: to convert membrane potential into a readily detectable optical signal.When expressed in a neuron or a cardiac myocyte, these voltage-indicating proteins convert electrical action potentials into visible flashes of fluorescence.We made movies of action potential propagation in primary neuronal cultures, in human iPS-derived neurons and cardiomyocytes, and in zebrafish embryos.We combined rhodopsin-based voltage indicators with channelrhodopsin-based optogenetic actuators to create an all-optical electrophysiology system.We developed computational techniques to map electrical propagation in neurons at effective frames rates up to 100,000 frames per second.


The genes, imaging systems, and analysis software enable studies of electrical dynamics in cells, tissues, and organisms with an information content and throughput that greatly exceed the capabilities of electrode-based devices.We are now working to apply these tools to screen drugs in stem cell-based models of neuropsychiatric and cardiac disease.


J. Kralj, D. R. Hochbaum, A. D. Douglass, A. E. Cohen, "Electrical spiking in Escherichia coli probed with a fluorescent voltage-indicating protein," Science, 333, 345-348 (2011) J. Kralj*, A. D. Douglass*, D. R. Hochbaum*, D. Maclaurin, A. E.


Cohen, "Optical recording of action potentials in mammalian neurons using a microbial rhodopsin," Nature Methods, 9, 90-95 (2012)