title: 980-nm infrared laser modulation of sodium channel kinetics in a neuron cell linearly mediated by photothermal effect.
abstract: Photothermal effect (PE) plays a major role in the near-infrared laser interaction with biological tissue. But, quite few interactions can be quantitatively depicted. Here, a two-step model is proposed to describe a 980-nm infrared laser interaction with neuron cell in vitro. First, the laser-induced temperature rises in the cell surrounding area were measured by using an open pipette method and also calculated by solving the heat conduction equation. Second, we recorded the modifications on sodium (Na) channel current in neuron cells directly by using a patch clamp to synchronize the 980-nm laser irradiation and obtained how the electrophysiological function of neuron cells respond to the temperature rise. Then, the activation time constants, τ(m), were extracted by fitting the sodium currents with the Hodgkin-Huxley model. The infrared laser modulation effect on sodium currents kinetics was examined by taking a ratio between the time constants with and without the laser irradiations. The analysis revealed that the averaged ratio at a specific laser exposure could be well related to the temperature properties of the Na channel protein. These results proved that the modulation of sodium current kinetics of a neuron cell in vitro by 980-nm laser with different-irradiation levels was linearly mediated corresponding to the laser-induced PE.
authors.affiliation: Dalian University of Technology, Lab of Biomedical Optics, College of Physics and Optoelectronic Engineering, Dalian 116023, China.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Li
authors.affiliation: Dalian University of Technology, Lab of Biomedical Optics, College of Physics and Optoelectronic Engineering, Dalian 116023, ChinabDalian University of Technology, Department of Biological Science and Technology, Dalian 116023, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.affiliation: Dalian University of Technology, Lab of Biomedical Optics, College of Physics and Optoelectronic Engineering, Dalian 116023, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Liang
authors.affiliation: Dalian University of Technology, Lab of Biomedical Optics, College of Physics and Optoelectronic Engineering, Dalian 116023, China.
authors.forename: Changsen
authors.initials: C
authors.lastname: Sun
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D006624:Hippocampus / Q000166:cytology; D007259:Infrared Rays; D008564:Membrane Potentials / Q000502:physiology / Q000528:radiation effects; D008959:Models, Neurological; D009474:Neurons / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015222:Sodium Channels / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects*
chemical_list: D015222:Sodium Channels