Optogenetic Functional MRI Dissection of Brain Networks and Properties

11:00am-12:00pm, Aug 13, 2019

Rudy North Lecture Theatre, Lower Level, Djavad Mowafaghian Centre for Brain Health
Presenter: 
Dr. Ed Wu, University of Hong Kong

Dr. Wu is the Lam Woo Professor and Chair of Biomedical Engineering at the University of Hong Kong (HKU). His research interests are in developing novel MRI methodologies for in vivo functional and microstructural characterization of biological systems, particularly the brain, by combing functional, diffusion and spectroscopy MRI with electrophysiology and emerging neuromodulation techniques such as optogenetics.

Abstract

One grand challenge for the 21st century is to achieve an integrated understanding of the brain circuits, particularly the spatiotemporal patterns of neural activities that give rise to functions, mental experience and behavior. Here we combine fMRI with optogenetics to capture and analyze whole brain activity and long-range circuits with much improved specificity and causality. We deploy this capability to systematically interrogate the spatiotemporal response properties of two distinct long-range networks, namely, thalamo-cortical and hippocampal-cortical networks. We examine the functional effects of low-frequency optogenetic stimulation within these two networks on brain responses to external sensory stimuli, on brain-wide functional connectivity at resting-state, and on cognitive behaviors. Our findings reveal that low frequency activity governs large-scale, brain-wide connectivity and interactions through long-range excitatory projections to coordinate the functional integration of remote brain regions. This low frequency phenomenon contributes to the neural basis of long-range functional connectivity as measured by rsfMRI. These findings also provide a fresh impetus to directly probe into the mysteries of the brain using fMRI and highly specific neural perturbation technologies.

Biography

Dr. Wu is the Lam Woo Professor and Chair of Biomedical Engineering at the University of Hong Kong (HKU). From 1990 to 2003, Dr. Wu worked in Columbia University on the 3D PET and high-field MRI system engineering, first as an Assistant Professor and later as an Associate Professor of Radiology and Biomedical Engineering. Dr. Wu joined HKU in 2003, where he has served Medical Engineering Program Director (2008-2013) and Associate Dean of Engineering (2013-2016). Dr. Wu’s present research focus is to develop novel MRI methodologies for in vivo functional and microstructural characterization of biological systems, particularly the brain, by combing functional, diffusion and spectroscopy MRI with electrophysiology and emerging neuromodulation techniques such as optogenetics. Dr. Wu is an elected Fellow of International Society for Magnetic Resonance in Medicine (ISMRM), IEEE, and AIMBE. He is the Asia Pacific Editor of NMR in Biomedicine since 2011, and Editorial Board Member of Magnetic Resonance in Medicine.