Fig. 1

Morphological changes in the left posterior cerebral artery (Lt PCA) prone to rupture and the inflammatory changes in the brain parenchyma adjacent to the Lt PCA. A Procedure for the induction of intracranial aneurysms, and representative photographs of SAH due to the rupture of aneurysms at the Lt PCA (right) and the anterior circle of Willis (aCW) (left). OVX oophorectomy, CAL carotid artery ligation, Rt RL/Lt RL right/left posterior renal artery ligation, SAH subarachnoid hemorrhage by aneurysm rupture, HSD high-salt diet, SD standard diet, SBP systolic blood pressure, IHC immunohistochemistry. B Morphological changes with an enlarged blood vessel (left) and a representative rupture (right) at the Lt PCA (dotted circle). The bar graph indicates the incidence of ruptured IAs at the aCW or Lt PCA within 6 weeks (n = 30). C Sagittal sections of unruptured IAs at the Lt PCA. Arrows indicate the diameter of the vessel lumen and vascular wall. D Expression of RAGE and Iba-1 in the brain parenchyma adjacent to the Lt PCA in representative sham-operated rats and rats with unruptured IAs (n = 5, each). E mRNA levels of RAGE, MR, and ATP1α3 in unruptured IAs (n = 6). Data are expressed as the mean ± standard deviation. *p < 0.05 vs. the sham-operated rats by the Student’s t test