Spontaneous cortical vasodynamics form a multiscale propagation architecture across the awake brain

Area of Science:

• Neuroimaging
• Vascular Biology
• Systems Neuroscience

Background:

• Spontaneous vascular dynamics are crucial for functional MRI (fMRI) signals.
• The systems-level propagation structure of these dynamics is not well understood.

Purpose of the Study:

• To map the propagation of vasodynamic activity across the awake mouse cortex.
• To investigate the multiscale organization of vascular dynamics using high-resolution fMRI.

Main Methods:

• Combined 14 T cerebral blood volume (CBV)-weighted fMRI with space-frequency singular value decomposition.
• Utilized ultra-fast fMRI for 3D mapping of phase gradients in cortical and radial axes.
• Analyzed frequency-specific oscillatory modes and vasodynamic propagation patterns.

Main Results:

• Identified vessel-aligned, frequency-specific oscillatory modes in CBV-fMRI data.
• Revealed multiscale vasodynamic propagation with tangential traveling waves and radial laminar timing.
• Demonstrated spatially structured, rather than homogeneous, vasodynamic distribution across the cortex at the group level.

Conclusions:

• Established a noninvasive framework for resolving multiscale vasodynamic propagation in the awake brain.
• Provided a foundation for studying cerebrovascular organization and dysfunction using vascularly specific fMRI.
• Highlighted the importance of spatially structured vasodynamics in brain function.