New research from Harvard Medical School and collaborators uncovered that specific endothelial gap junction proteins, connexins Cx37 and Cx40, enable rapid communication along brain blood vessels, coordinating vasodilation to active neural regions in mice. Using optogenetics and gene deletion models, scientists showed these connexins are essential for neurovascular coupling and proper blood flow regulation. Findings, published in Cell, could inform studies on neurodegeneration and cerebrovascular diseases.