title: Light distribution and thermal effects in the rat brain under optogenetic stimulation.
abstract: Optical brain stimulation gained a lot of attention in neuroscience due to its superior cell-type specificity. In the design of illumination strategies, predicting the light propagation in a specific tissue is essential and requires knowledge of the optical properties of that tissue. We present the estimated absorption and reduced scattering in rodent brain tissue using non-destructive contact spatially resolved spectroscopy (cSRS). The obtained absorption and scattering in the cortex, hippocampus and striatum are similar, but lower than in the thalamus, leading to a less deep but broader light penetration profile in the thalamus. Next, the light distribution was investigated for different stimulation protocols relevant for fiber-optic based optogenetic experiments, using Monte Carlo simulation. A protocol specific analysis is proposed to evaluate the potential of thermally induced side effects.
authors.affiliation: Department of Physics and Astronomy, University of Leuven, Celestijnenlaan 200D, 3001, Leuven, Belgium. barbara.gysbrechts@fys.kuleuven.be.
authors.forename: Barbara
authors.initials: B
authors.lastname: Gysbrechts
authors.affiliation: Department of Physics and Astronomy, University of Leuven, Celestijnenlaan 200D, 3001, Leuven, Belgium.
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Biosystems, University of Leuven, Kasteelpark Arenberg 30, 3001, Leuven, Belgium.
authors.forename: Nghia Nguyen Do
authors.initials: NN
authors.lastname: Trong
authors.affiliation: Donders Institute, Radboud University, Heyendaalseweg 135, 6525, AJ Nijmegen, The Netherlands.
authors.forename: Henrique
authors.initials: H
authors.lastname: Cabral
authors.affiliation: Donders Institute, Radboud University, Heyendaalseweg 135, 6525, AJ Nijmegen, The Netherlands.
authors.forename: Zaneta
authors.initials: Z
authors.lastname: Navratilova
authors.affiliation: Donders Institute, Radboud University, Heyendaalseweg 135, 6525, AJ Nijmegen, The Netherlands.
authors.forename: Francesco
authors.initials: F
authors.lastname: Battaglia
authors.affiliation: Department of Biosystems, University of Leuven, Kasteelpark Arenberg 30, 3001, Leuven, Belgium.
authors.forename: Wouter
authors.initials: W
authors.lastname: Saeys
authors.affiliation: Department of Physics and Astronomy, University of Leuven, Celestijnenlaan 200D, 3001, Leuven, Belgium.
authors.forename: Carmen
authors.initials: C
authors.lastname: Bartic
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D005336:Fiber Optic Technology; D008027:Light; D009010:Monte Carlo Method; D062308:Optogenetics; D051381:Rats
keywords: light propagation in tissues; optogenetics; photothermal effects; spectroscopy; tissue characterization