Neurotoxicity of Deltamethrin on Zebrafish in Early Developmental Stage
Deltamethrin(DM)has been widely used as a type Ⅱ pyrethroid insecticide.Its high lipophilicity allows it to easily pass through the blood-brain barrier and affect the nervous system.However,its impact on the early neural development of zebrafish and the mechanism of toxicity remains unclear.In this study,zebrafish(Danio rerio)embryos were exposed to DM with different concentration of 0,10,20 and 50 μg·L-1 to analyze the develop-ment and movement ability.The neurotoxicity of DM to zebrafish larvae was evaluated on the development of the nerve cells of transgenic zebrafish line.The results showed that the frequency of spontaneous coiling decreased 41.2％(P＜).001)by 50 μg·L-1DM exposure at 24 hpf.The hatching rate of all the DM exposure groups was higher than the control group and heart rate were significantly increased in 20 and 50 μg·L-1 groups(P＜0.01,P＜0.0001),and the body length was significantly reduced(P＜0.01)at 36 hpf.These results showed that the effect of DM on embryo development was dose-dependent.Through the analysis of the spontaneous swim,light-dark stimulus and open field behavior of zebrafish larvae,it was found that zebrafish larvae became sluggish in those three scenarios,indicating that DM exposure affected the mobility of zebrafish,and the ability to respond to external environmental stimuli and the ability to actively explore new environments was weakened.Further analysis of transgenic zebrafish strains with specific markers for neural cell systems found that DM exposure caused a significant decrease in the number of nerve stem/progenitor cells in zebrafish(P＜0.01,P＜0.001),neuronal cell activity was enhanced,and the number of apoptotic cells was significantly increased(P＜0.0001).The results suggested that the neurotoxicity of zebrafish larvae induced by DM is related to the nerve cell viability.DM is toxic to the central nervous system of zebrafish by destroying the number of nerve stem/progenitor cells,over-activating neurons and promoting apoptosis of nerve cells,thus affecting the behavior of zebrafish embryos and larvae.
NETL
NSTL
万方数据
