Distinct laminar neurovascular and metabolism responses across eccentricity revealed by multi-contrast visual fMRI at 7T

Motivation: To better understand the complex interplay between neurovascular responses and metabolism. Goal(s): The goal was to develop a multi-contrast laminar fMRI tool to concurrently measure CBF, CBV, BOLD, and CMRO2 signals. Approach: We employed a novel pulse sequence to simultaneously acquire ASL CBF, VASO CBV, and T2-BOLD signals at a high spatial resolution of 7T. We also incorporated a calibrated fMRI approach (Davis model) to calculate CMRO2, using parameters estimated from breath-hold induced hypercapnia. Results: We found distinct neurovascular and metabolic responses across cortical layers and eccentricities in response to a ring-shaped visual stimulus. Impact: Multi-contrast laminar fMRI significantly impacts neuroscientific research by providing a more comprehensive understanding of neurovascular (CBF, CBV, BOLD) and metabolic (CMRO2) interactions across cortical layers. It opens doors for exploring complex brain functions and disorders.