Connectomes across temporal scales with simultaneous wide-field optical imaging and resting-state functional MRI

Area of Science:

• Neuroscience
• Biophysics

Background:

• Resting-state functional MRI (rs-fMRI) is crucial for brain research.
• Its interpretation is challenging due to the slow hemodynamic response, which can obscure neural activity at faster timescales.

Purpose of the Study:

• To directly investigate the relationship between neural and hemodynamic functional connectomes across different timescales.
• To compare the reliability of time-resolved rs-fMRI and hemodynamic wide-field optical imaging (WOI) signals against neural activity.

Main Methods:

• Simultaneous wide-field optical imaging (WOI) and rs-fMRI were employed.
• Analysis focused on comparing functional connectivity across modalities and timescales.

Main Results:

• Large-scale spatial structure is largely preserved across modalities (WOI and rs-fMRI), timescales, and frequencies.
• rs-fMRI effectively captures time-averaged neural activity, but time-resolved estimates show higher variability.
• Hemodynamic WOI signals show greater similarity to neural activity than rs-fMRI, especially at lower frequencies.

Conclusions:

• The time-averaged spatial structure of neural activity is reliably represented by both hemodynamics and rs-fMRI.
• Findings offer insights into the reliability of time-resolved rs-fMRI across temporal scales.
• A multimodal framework is established for validating dynamic brain activity features.