Cerebral artery dilation during transient ischemia is impaired by amyloid β deposition around the cerebral artery in Alzheimer's disease model mice.

Transient ischemia is an exacerbation factor of Alzheimer's disease (AD). We aimed to examine the influence of amyloid β (Aβ) deposition around the cerebral (pial) artery in terms of diameter changes in the cerebral artery during transient ischemia in AD model mice (APPNL-G-F) under urethane anesthesia. Cerebral vasculature and Aβ deposition were examined using two-photon microscopy. Cerebral ischemia was induced by transient occlusion of the unilateral common carotid artery. The diameter of the pial artery was quantitatively measured. In wild-type mice, the diameter of arteries increased during occlusion and returned to their basal diameter after re-opening. In AD model mice, the artery response during occlusion differed depending on Aβ deposition sites. Arterial diameter changes at non-Aβ deposition site were similar to those in wild-type mice, whereas they were significantly smaller at Aβ deposition site. The results suggest that cerebral artery changes during ischemia are impaired by Aβ deposition.