Abstract #0654

Non-Specific Effects in OfMRI: Characterising the fMRI Signal Responses to 445 Nm Light Delivered Via Optic Fibers

Isabel N. Christie¹,², Jack A. Wells³, Nephtali Marina¹, Sergey Kasparov⁴, Alexander V. Gourine¹, Mark F. Lythgoe³

¹Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom; ²UCL Centre for Advanced Biomedical Imaging, Division of Medicine and Institute of Child Health, University College London , London, United Kingdom; ³UCL Centre for Advanced Biomedical Imaging, Division of Medicine and Institute of Child Health, University College London, London , United Kingdom; ⁴School of Physiology and Pharmacology, University of Bristol (IC and JW joint first authors, SK,AG,ML joint senior authors)

This study documents marked non-specific effects of light delivered to the cortex with fMRI. With regard to opMRI such artefacts could confound genuine optogenetically induced hemodynamic changes. Functional MRI responses can be observed using established light delivery protocols, which has profound implications for the design and interpretation of combined optogenetic and MRI experiments.