Dissection of brain-wide resting-state and functional somatosensory circuits by fMRI with optogenetic silencing

Abstract

Significance Functional MRI (fMRI) has led to tremendous advancements in brain science by allowing noninvasive mapping of functional regions in response to various stimuli and noninvasive mapping of resting-state functional connectivity. Both evoked and resting-state functional networks contain multiple brain regions that are hierarchically yet reciprocally connected. Therefore, it is critical to determine the relative contributions of different circuits to fMRI findings to better understand brain functions and resting-state connectivity. Here, we adopted local silencing with optogenetic stimulation to suppress downstream networks and successfully dissected fMRI responses at the circuit level. This fMRI approach opens an avenue for understanding brain-wide, population-based neural circuits, allowing investigations of functional reorganization caused by neuropathological modifications and learning in individual animals.