Altered Neurovascular Coupling Dynamics During Dobutamine-Induced Acute Stress.

BACKGROUND: Neurovascular coupling (NVC) is essential for regulating brain metabolism and energy supply and may be altered under acute stress. This study aimed to investigate how acute stress induced by dobutamine affects NVC. MATERIALS AND METHODS: This study enrolled 38 healthy participants undergoing a resting-state fMRI scan and an arterial spin labeling MRI scan prior to and during a stress test induced by dobutamine. Amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), and cerebral blood flow (CBF) were calculated. Acrossvoxel CBF-ReHo and CBF-ALFF correlations were analyzed to evaluate the NVC within the whole gray matter, and the regional NVC of the brain was assessed with the CBF/ReHo and CBF/ALFF ratios. RESULTS: The blood pressures at the ventricle systolic state (SBP) and diastolic state (DBP) were significantly increased after the infusion of dobutamine. The CBF/ReHo ratios in the postcentral cortex and the middle cingulate cortex under stress were significantly higher and lower, respectively, than the CBF/ReHo ratios in the postcentral cortex and the middle cingulate cortex under the resting state. Logistic regression analysis showed that DBP in the resting state (odds ratio [OR] 0.817, 95% confidence interval [CI] 0.692-0.965, p = 0.017) and SBP in the stress state (OR 1.218, 95% CI 1.067-1.390, p = 0.004) were significantly related to the increase in CBF/ReHo ratios in the left postcentral cortex. CONCLUSION: Dobutamine-induced acute stress modulated NVC dynamics. Participants with lower DBP in the resting state and higher SBP during acute stress were more prone to have increased NVC induced by stress. RELEVANCE STATEMENT: Acute cardiovascular stress induced by dobutamine altered neurovascular coupling dynamics, and individuals with lower resting diastolic pressure and greater systolic responses showed stronger stress-related NVC enhancement.