Approximately 350,000 chemicals are predicted to be commercially available worldwide. Little is known about which chemicals are potentially neurotoxic, meaning harmful to the (developing) brain. To date, efficient testing methods are lacking. A research team at the Helmholtz-Centre for Environmental Research (UFZ) has now developed a screening approach based on the zebrafish embryo model that enables high-throughput neurotoxicity testing without the need for conventional animal experiments.