Toward an integrative neurovascular framework for studying brain networks

Area of Science:

• Neuroimaging
• Systems Neuroscience
• Biophysics

Background:

• Blood oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) is a key tool for mapping human brain functional connectivity.
• Recent studies question the neuronal basis of resting-state networks, suggesting vascular or physiological signals can replicate them.
• Understanding the origin of BOLD signals is crucial for accurate brain network interpretation.

Purpose of the Study:

• To investigate the interaction between vascular and neuronal systems in generating BOLD fMRI signals.
• To re-evaluate the role of the vascular network in brain functional connectivity.
• To integrate vascular information into models of functional connectivity.

Main Methods:

• Review of brain network analysis concepts.
• Exploration of vascular-neuronal system interactions in BOLD fMRI.
• Multiscale and multimodal optical imaging in mice.
• Computational modeling integrating vascular data.

Main Results:

• BOLD fMRI signals reflect an interplay between neuronal activity and vascular dynamics.
• The brain's vascular network is not merely a confounder but a functionally relevant system.
• Functional connectivity patterns are influenced by the entanglement of vascular and neuronal networks.

Conclusions:

• The vascular system plays a significant, integrated role in BOLD-based functional connectivity.
• A comprehensive understanding of brain networks requires considering both neuronal and vascular contributions.
• Multimodal imaging and computational modeling offer powerful approaches to disentangle these contributions.