EXPRESS: Trifluoperazine reduces infarct size, restores neurovascular coupling and improves early outcomes in experimental acute ischemic stroke

Cerebral edema and neurovascular dysfunction are reliable predictors of outcome after acute ischemic stroke (AIS), yet effective targeted therapies remain limited. We investigated the therapeutic potential of trifluoperazine (TFP), an FDA-approved antipsychotic and calmodulin inhibitor that modulates astrocytic aquaporin-4 expression. TFP administered after recanalization in a mouse model of AIS reduced infarct volume and improved early neurological recovery. Importantly, TFP restored neurovascular coupling and enhanced cerebral blood flow responses to spreading depolarizations, indicating improved cerebrovascular function. Mechanistic studies in acute brain slice preparations demonstrated that TFP attenuates cytotoxic tissue swelling, suppresses spreading depolarizations, reduces aquaporin-4 expression and preserves neuronal integrity under osmotic stress. These findings suggest that transient modulation of astrocytic cytotoxic edema and vascular reactivity represents a viable strategy to improve early stroke outcomes. Given its established clinical use, TFP emerges as a promising candidate for therapeutic repurposing in AIS.