Optical excitation and detection of neuronal activity

Chenfei Hu, Richard Sam, Mingguang Shan, Viorel Nastasa, Minqi Wang, Taewoo Kim, Martha Gillette, Parijat Sengupta, Gabriel Popescu

Research output: Contribution to journalArticlepeer-review


Optogenetics has emerged as an exciting tool for manipulating neural activity, which in turn, can modulate behavior in live organisms. However, detecting the response to the optical stimulation requires electrophysiology with physical contact or fluorescent imaging at target locations, which is often limited by photobleaching and phototoxicity. In this paper, we show that phase imaging can report the intracellular transport induced by optogenetic stimulation. We developed a multimodal instrument that can both stimulate cells with subcellular spatial resolution and detect optical pathlength (OPL) changes with nanometer scale sensitivity. We found that OPL fluctuations following stimulation are consistent with active organelle transport. Furthermore, the results indicate a broadening in the transport velocity distribution, which is significantly higher in stimulated cells compared to optogenetically inactive cells. It is likely that this label-free, contactless measurement of optogenetic response will provide an enabling approach to neuroscience.

Original languageEnglish (US)
Article numbere201800269
JournalJournal of Biophotonics
Issue number3
StatePublished - Mar 2019


  • cell activation
  • intracellular transport
  • label-free imaging
  • optogenetics
  • quantitative phase imaging

ASJC Scopus subject areas

  • General Chemistry
  • General Materials Science
  • General Biochemistry, Genetics and Molecular Biology
  • General Engineering
  • General Physics and Astronomy


Dive into the research topics of 'Optical excitation and detection of neuronal activity'. Together they form a unique fingerprint.

Cite this