Effects of Aquaporin-4 Inhibition on Relative Cerebrovascular Reactivity using Resting-state Functional MRI

Aquaporin-4 (AQP4) is most abundant water channel responsible for cerebrospinal fluid influx in the brain, and has important bearings on cerebrovascular diseases. However, it remains unclear how aquaporin-4 functions in the cerebrovasculature. We used relative cerebrovascular reactivity (rCVR) mapping derived from task-free, resting-state blood-oxygenation-level-dependent functional MRI to determine the effects of AQP4 suppression on the healthy mouse brains using the AQP4 inhibitor TGN020. We observed different patterns of rCVR responses across cortical and subcortical brain regions, indicating the heterogeneity of AQP4 functions in the cerebrovasculature, which may explain the varying vulnerability of different brain regions to cerebrovascular diseases.