Vascular endothelial cell-expressing molecules regulate neuronal function. Although cerebrovascular dysregulation is a hallmark of Alzheimer's disease (AD), the effect of changes in molecular expression on neuronal function in vascular endothelial cells during disease progression is not clear. In this study, we demonstrated that the cellular communication network factor 1 (CCN1), which is highly expressed in vascular endothelial cells during the chronic stage of AD in mice, is involved in the impairment of cognitive function. Vascular endothelial cells isolated from the brains of App