Abstract

Motivation: Neuronal activity induces vasodilation in local arterioles that propagates to upstream large arteries, but the furthest detectable arterial dilation from the site of neuronal activity remains unknown. Goal(s): Detecting blood velocity responses at far upstream branches of the Posterior Cerebral Artery induced by a visual stimulus. Approach: In this study, a functional phase-contrast MRA technique was combined with a commonly used block-design stimulation paradigm to detect blood velocity responses. Results: About 10–20% velocity increases at the P2 segments of the Posterior Cerebral Artery were robustly observed. Impact: We demonstrate that neuronal activity-induced velocity response can propagate to large feeding arteries 6–7 cm from the visual cortex. The spatial and temporal properties of this propagation are important for understanding neurovascular coupling, autoregulation, and human fMRI.