The Challenge and Opportunities of Mapping Cortical Layer Activity and Connectivity with fMRI
A major outstanding challenge in neuroscience is to integrate across levels of investigation, linking genes, molecules, cells, microcircuits, regions, systems and behavior. This will require bringing together evidence from sources across different spatial scales—from the microscopic, such as electrophysiological recordings in animals, to the macroscopic, such as conventional neuroimaging in humans. The mesoscale technique of depth-dependent fMRI, or “layer fMRI” which can be applied non-invasively in awake, behaving humans, is a critical missing link to bridge this gap. Specifically, layer fMRI has the potential to open up human neuroimaging research as functional information at the layer-level allows not only for inferences to be made about location of activation but also for inferences to be made on feedforward and feedback activity from each region, based on our knowledge of the organization of cortical layers. These inferences may therefore better inform network models, provide insights into the functional causality of specific regions, and to provide informative maps of cortical hierarchy.
In this talk, Dr. Peter Bandettini outlines the technical challenges and current solutions to layer fMRI. Specifically, Dr. Bandettini describes his group's acquisition strategies for maximizing resolution, spatial coverage, time efficiency as well as, perhaps most importantly, vascular specificity. Novel applications from his group, including mapping feedforward and feedback connections to M1 during task and sensory input modulation and S1 during a sensory prediction task are be shown. Layer specific activity in dorsal lateral prefrontal cortex during a working memory task is also demonstrated. Additionally, Dr. Bandettini shows preliminary work on mapping whole brain layer-specific resting state connectivity and hierarchy.
Lastly, Dr. Bandettini outlines the ongoing and future challenges and opportunities of layer fMRI. Layer fMRI promises to provide new insight into human cortical processing and information about individual differences and mechanisms of pathology.
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Dr. Peter Bandettini
Dr. Peter Bandettini is Chief of Section on Functional Imaging Methods, and Director of Functional Magnetic Resonance Imaging Core Facility (FMRIF) at National Institute of Mental Health (NIMH).
Publication Year: 2021