A drug commonly used to treat glaucoma has been shown in zebrafish and mice to protect against the build-up in the brain of the protein tau, which causes various forms of dementia and is implicated in Alzheimer’s disease. Researchers in the UK Dementia Research Institute at the University of Cambridge screened more than 1,400 clinically-approved drug compounds using zebrafish genetically engineered to make them mimic so-called tauopathies. They discovered that drugs known as carbonic anhydrase