Selectively Impaired Vasodilation of Human White Matter Penetrating Cerebral Arterioles in Microvascular Brain Injury and Alzheimer's disease

Abstract

Microvascular brain injury (mVBI) is a common pathologic correlate of vascular contributions to cognitive impairment and dementia (VCID) that leads to white matter (WM) injury. VCID appears to arise from chronic recurrent WM ischemia. We hypothesized that in mVBI WM injury is specifically attributed to vasodilator dysfunction of WM penetrating arterioles. We analyzed 38 cases of mVBI with low and high Alzheimer's disease (AD) neuropathologic changes in prefrontal cortex WM from rapid autopsies in a population‐based cohort where VCID and AD frequently occur. Arteriolar vasodilator function was quantified by videomicroscopy. Acetylcholine‐mediated arteriolar dilation in mVBI with low AD pathology was significantly reduced in WM penetrators relative to pial arterioles. Astrogliosis‐defined WM injury was associated with impaired vasodilator function of WM penetrating arterioles. In mVBI with high AD pathology vasodilator function of WM penetrating arterioles was further diminished. Presence of moderate/frequent neuritic plaques and cerebral amyloid angiopathy were associated with impaired dilation in WM penetrating, but not in pial arterioles. In conclusion, we successfully assessed vasodilator function of human WM penetrating arterioles in postmortem rapid autopsy samples. We found that selectively impaired vasodilator function of WM penetrating arterioles in mVBI occurs in association with WM injury and AD neuropathologic change.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.