Microvascular structure variability explains variance in fMRI functional connectivity.

Area of Science:

• Neuroscience
• Medical Imaging
• Systems Biology

Background:

• Resting-state functional magnetic resonance imaging (fMRI) BOLD signals are known to be influenced by regional brain vasculature.
• However, the specific role of vasculature in functional connectivity (FC) research is often underestimated.
• Understanding this relationship is crucial for interpreting fMRI data and neurological conditions.

Purpose of the Study:

• To investigate the relationship between brain vasculature and functional connectivity in mice.
• To introduce and utilize a novel metric, vascular similarity, to quantify interregional vascular variations.
• To determine if vascular similarity improves models predicting functional connectivity.

Main Methods:

• Utilized publicly available whole-brain vasculature data from mice.
• Identified features to describe regional vasculature and calculated vascular similarity.
• Employed multiple linear regression models incorporating vascular similarity, structural connectivity, and spatial topology to predict functional connectivity.
• Analyzed data at both cerebrum and whole-brain levels, including male and female mice.

Main Results:

• A significant correlation was found between functional connectivity strength and regional vascular similarity, especially in anesthetized mice.
• Multiple linear regression models predicting functional connectivity were improved by the inclusion of vascular similarity.
• The findings were consistent across cerebrum and whole-brain analyses and in both male and female mice.

Conclusions:

• Brain vascular anatomy is a significant determinant of functional connectivity.
• Incorporating vascular similarity enhances the predictive power of functional connectivity models.
• These findings may improve the interpretation of fMRI studies and offer insights into neurological disorders related to vascular changes.