Keywords: 
• zebrafish /
• cadmium chloride /
• toxicity /
• neural behavior /
• video tracking /
• larva

Abstract: To realize the developmental neurotoxicity of cadmium on zebrafish embryos and larvae, the neurobehavioral response of individual zebrafish larva (6 days post-fertilization) in 48-well microtiter plates was investigated after cadmium chloride (0.5-2.0 μmol·L^-1) administered to the embryos (36 hours post-fertilization) by immersion. Movement of larvae were recorded and analyzed by using a video-tracking system. Results showed that low-concentration cadmium chloride evokes the spontaneous movement tracks of larvae disorder. The tereotypic circling swimming of larvae increased, but the touching wall response reduced in range of 0.1-0.5 μmol·L^-1 exposure dose. Larvae represented motorial inhibition, tremor and freezing at 1.0 μmol·L^-1 cadmium chloride. Moreover, the distance moved of larvae showed the "Inverted U" dose-response to the concentration of cadmium chloride, which the locomotor activity pattern was similar to that caused by acute ethanol exposure. Light-evoked startle escape response results showed that cadmium chloride can promote or reduce the sensibility of larvae to light or dark transition. Accordingly, the habituation of activity presented postpone or accelerate in dark after light stimulation. These results demonstrated that the development of nerve of zebrafish embryos and larvae were sensitive to toxicity of cadmium chloride. In addition, zebrafish larvae were a type of powerful model in developmental neurotoxicity of exogenous assessment by using high-throughput neurobehavioral detections.