Liu_2025_Environ.Pollut__126782

Short-chain chlorinated paraffins (SCCPs) are a series of persistent, bioaccumulative and toxic (PBT) substances that are widely distributed in the environment. However, little information is available on SCCPs neurotoxicity. In present research, adult male zebrafish (Danio rerio) were used as a model and exposed to 0, 50, or 250 microg/L SCCPs for 21 days to investigate the neurotoxicity effect of SCCPs. We evaluated the swimming behavior traits, acetylcholinesterase (AChE) levels, neuroinflammatory response, tight junction-related mRNA and protein levels and blood-brain barrier (BBB) ultrastructural changes of fish following 21 days of SCCPs exposure. Our research showed that SCCPs significantly weakened swimming ability and locomotor activity of zebrafish, activated the neuroinflammatory response, decreased AChE content and activity, and the tight junction-related mRNA and protein levels in the fish brain. In addition, the results of transmission electron microscopy (TEM) revealed the ultrastructural changes of BBB and brain cell apoptosis in zebrafish, further proving that chronic exposure to SCCPs can cause BBB damage. In summary, this study focused on the chronic exposure of zebrafish to SCCPs, revealing that such exposure can damage the BBB and lead to nerve injury, and will provide important insights into the potential health risks associated with SCCPs and emphasize the necessity for further research.