KDR and Hydrocephalus: This study demonstrates these findings as follows: (1) the internalization and reduction of membrane VE–cadherin in choroid plexus contributed to IVH-induced hydrocephalus; (2) metformin inhibited VEGF/VEGFR2/p-Src pathway activation and reversed the internalization of VE–cadherin, thereby ameliorated IVH-induced hydrocephalus.