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 beta (A beta) deposition around the cerebral (pial) artery in terms of diameter changes in the cerebral artery during transient ischemia in AD model mice (APP(NL-G-F)) under urethane anesthesia. Cerebral vasculature and A beta 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 A beta deposition sites. Arterial diameter changes at non-A beta deposition site were similar to those in wild-type mice, whereas they were significantly smaller at A beta deposition site. The results suggest that cerebral artery changes during ischemia are impaired by A beta deposition.