title: Calcium imaging of infrared-stimulated activity in rodent brain.
abstract: Infrared neural stimulation (INS) is a promising neurostimulation technique that can activate neural tissue with high spatial precision and without the need for exogenous agents. However, little is understood about how infrared light interacts with neural tissue on a cellular level, particularly within the living brain. In this study, we use calcium sensitive dye imaging on macroscopic and microscopic scales to explore the spatiotemporal effects of INS on cortical calcium dynamics. The INS-evoked calcium signal that was observed exhibited a fast and slow component suggesting activation of multiple cellular mechanisms. The slow component of the evoked signal exhibited wave-like properties suggesting network activation, and was verified to originate from astrocytes through pharmacology and 2-photon imaging. We also provide evidence that the fast calcium signal may have been evoked through modulation of glutamate transients. This study demonstrates that pulsed infrared light can induce intracellular calcium modulations in both astrocytes and neurons, providing new insights into the mechanisms of action of INS in the brain.
authors.affiliation: Department of Biomedical Engineering, Vanderbilt University, Station B, Box 351631, Nashville TN 37235, United States.
authors.forename: Jonathan Matthew
authors.initials: JM
authors.lastname: Cayce
authors.affiliation: Laboratory for Functional Optical Imaging, Departments of Biomedical Engineering and Radiology, Columbia University, 120th Street and Amsterdam Avenue, New York, NY 10027, United States.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Bouchard
authors.affiliation: Department of Biomedical Engineering, Vanderbilt University, Station B, Box 351631, Nashville TN 37235, United States.
authors.forename: Mykyta M
authors.initials: MM
authors.lastname: Chernov
authors.affiliation: Laboratory for Functional Optical Imaging, Departments of Biomedical Engineering and Radiology, Columbia University, 120th Street and Amsterdam Avenue, New York, NY 10027, United States.
authors.forename: Brenda R
authors.initials: BR
authors.lastname: Chen
authors.affiliation: Laboratory for Functional Optical Imaging, Departments of Biomedical Engineering and Radiology, Columbia University, 120th Street and Amsterdam Avenue, New York, NY 10027, United States.
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Grosberg
authors.affiliation: Department of Biomedical Engineering, Vanderbilt University, Station B, Box 351631, Nashville TN 37235, United States.
authors.forename: E Duco
authors.initials: ED
authors.lastname: Jansen
authors.affiliation: Laboratory for Functional Optical Imaging, Departments of Biomedical Engineering and Radiology, Columbia University, 120th Street and Amsterdam Avenue, New York, NY 10027, United States.
authors.forename: Elizabeth M C
authors.initials: EM
authors.lastname: Hillman
authors.affiliation: Department of Biomedical Engineering, Vanderbilt University, Station B, Box 351631, Nashville TN 37235, United States. Electronic address: anita.mahadevan-jansen@vanderbilt.edu.
authors.forename: Anita
authors.initials: A
authors.lastname: Mahadevan-Jansen
mesh_terms: D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D004558:Electric Stimulation; D005463:Fluoroacetates / Q000737:chemistry / Q000494:pharmacology; D066298:In Vitro Techniques; D007259:Infrared Rays; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D005463:Fluoroacetates; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D002118:Calcium
keywords: Astrocytes; Calcium dye imaging; Calcium signaling; Infrared neural stimulation; Neurons; Optical imaging; Somatosensory cortex