Short infrared laser pulses increase cell membrane fluidity

Alex J. Walsh, Jody C. Cantu, Bennett L. Ibey, Hope T. Beier

Research output: Chapter in Book/Report/Conference proceedingConference contribution

11 Scopus citations


Short infrared laser pulses induce a variety of effects in cells and tissues, including neural stimulation and inhibition. However, the mechanism behind these physiological effects is poorly understood. It is known that the fast thermal gradient induced by the infrared light is necessary for these biological effects. Therefore, this study tests the hypothesis that the fast thermal gradient induced in a cell by infrared light exposure causes a change in the membrane fluidity. To test this hypothesis, we used the membrane fluidity dye, di-4-ANEPPDHQ, to investigate membrane fluidity changes following infrared light exposure. Di-4-ANEPPDHQ fluorescence was imaged on a wide-field fluorescence imaging system with dual channel emission detection. The dual channel imaging allowed imaging of emitted fluorescence at wavelengths longer and shorter than 647 nm for ratiometric assessment and computation of a membrane generalized polarization (GP) value. Results in CHO cells show increased membrane fluidity with infrared light pulse exposure and this increased fluidity scales with infrared irradiance. Full recovery of pre-infrared exposure membrane fluidity was observed. Altogether, these results demonstrate that infrared light induces a thermal gradient in cells that changes membrane fluidity.

Original languageEnglish (US)
Title of host publicationOptical Interactions with Tissue and Cells XXVIII
EditorsE. Duco Jansen, Hope Thomas Beier
ISBN (Electronic)9781510605657
StatePublished - 2017
EventOptical Interactions with Tissue and Cells XXVIII - San Francisco, United States
Duration: Jan 30 2017Jan 31 2017

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferenceOptical Interactions with Tissue and Cells XXVIII
Country/TerritoryUnited States
CitySan Francisco


  • cell membrane
  • di-4-ANEPPDHQ
  • fluidity
  • infrared neural stimulation
  • permeability

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging


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