title: Modeling the Spatiotemporal Dynamics of Light and Heat Propagation for In Vivo Optogenetics.
abstract: Despite the increasing use of optogenetics in vivo, the effects of direct light exposure to brain tissue are understudied. Of particular concern is the potential for heat induced by prolonged optical stimulation. We demonstrate that high-intensity light, delivered through an optical fiber, is capable of elevating firing rate locally, even in the absence of opsin expression. Predicting the severity and spatial extent of any temperature increase during optogenetic stimulation is therefore of considerable importance. Here, we describe a realistic model that simulates light and heat propagation during optogenetic experiments. We validated the model by comparing predicted and measured temperature changes in vivo. We further demonstrate the utility of this model by comparing predictions for various wavelengths of light and fiber sizes, as well as testing methods for reducing heat effects on neural targets in vivo.
authors.affiliation: Graduate Program in Neurobiology and Behavior, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA. Electronic address: jms2317@columbia.edu.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Stujenske
authors.affiliation: Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10021, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Spellman
authors.affiliation: Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, NY 10032, USA; Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA. Electronic address: jg343@columbia.edu.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Gordon
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D006358:Hot Temperature; D008027:Light; D051379:Mice; D008962:Models, Theoretical; D009474:Neurons / Q000502:physiology; D062308:Optogenetics / Q000379:methods*; D062211:Spatio-Temporal Analysis