Bridge the functional and hemodynamic brain mapping with multi-modal fMRI

In this talk, I will introduce the combination of the advanced fMRI method with the emerging neurotechniques to decipher the neuro-glial-vascular (NGV) coupling basis of brain state dynamics. First, we will see through the large voxel acquired from conventional fMRI method to decipher the contribution from distinct vascular components to the fMRI signal. A newly developed single-vessel fMRI method allows identifying the activity-evoked hemodynamic signal propagation through cerebrovasculature in the deep layer cortex, as well as the hippocampal vasculature, with either normal sensory inputs or optogenetic activation. Also, we have developed a line-scanning fMRI method to measure the laminar-fMRI across different cortical regions. Second, we will combine the fMRI with the optical fiber-mediated calcium recordings to decipher the cell-type specific contribution to the fMRI signal from neurons and astrocytes. Meanwhile, we will also show how extracellular glutamate can be recorded simultaneously to mediate NGV interaction. In addition, this multi-modal fMRI setup can be performed with both single-vessel and line-scanning fMRI to better characterize the hemodynamic responses underlying the fMRI signal. Finally, we are going to present how the global fMRI signal fluctuation can be linked to the brain state changes. We merge the pupillometry with the multi-modal fMRI to examine the detailed arousal index by pupil dynamics and fMRI fluctuation. In addition, we also studied the brain state recovery in a brainstem-induced rat coma model with the multi-modal fMRI platform. The series of work leads to the design of MRI-guided robotic arms to guide the deep brain optogenetic stimulation to modify the brain state, as well as an fMRI-based biofeedback control system to optimize the outcome of the treatment