Trimethyltin chloride (TMT) neurobehavioral toxicity in embryonic zebrafish

Trimethyltin chloride (TMT) is a neurotoxicant that is widely present in the aquatic environment, primarily from the manufacture of PVC plastic, but few studies have evaluated aquatic neurotoxicity. We have examined TMT dose-dependent malformation and neurobehavioral toxicity in the embryonic zebrafish model. Exposure of embryos to TMT (0-10 microM) from 48 to 72 hours post fertilization (hpf) elicited a concentration-related increase (0-100%) in malformation incidence with an EC(25) of 5.55 microM. TMT also significantly modulated the frequency of tail flexion, the earliest motor behavior observed in developing zebrafish, and the ability to respond to a mechanical tail touch. Exposure to 5 microM TMT from 48 to 72 hpf modulated the photomotor response at 4 and 5 days post fertilization and significantly promoted apoptosis in the tail. Our study demonstrates the morphological and behavioral sensitivity of the developing zebrafish to TMT and establishes a platform for future identification of the affected pathways and chemical modulators of TMT toxicity.