Zebrafish embryos exposed to chlorpyrifos; behavioral dataset

Organophosphates (OPs) are widely used insecticides that pose a great risk on human health and the ecosystem. These substances have neurotoxic mechanisms of action and, therefore, can alter the normal activity and function of the nervous system, unfortunately also in non-target species. Hence, the aim of the present study was to gain a better understanding of the neurotoxic mechanisms of organophosphates in non-target species using zebrafish (Danio rerio) embryos as a non-animal model. To determine the toxic responses of OPs, a study analysis has been conducted using the insecticide chlorpyrifos. Neurotoxic effects have been determined by assessing in vivo effects on developing zebrafish at 5-days post fertilization according to an adapted version of the test protocol for the Fish Embryo Acute Toxicity (FET) test OECD Guideline for the Testing of Chemicals no. 236. In addition, alterations of the swimming behavior in response to a stimulus were measured as an indicator for neurotoxicity. The average swimming distances of exposed embryos were significantly lower compared to the control embryos, indicating that organophosphates cause neurological dysfunction. The findings from the experimental behavioral data were combined with a literature search to establish an adverse outcome pathway (AOP) for organophosphate toxicity. The result suggests that acute OP exposure plausibly inhibited the enzyme function of acetylcholinesterase (AChE), resulting in an overstimulation of the neurotransmitter acetylcholine. This presumably caused the swimming behavior deficits of CPF exposed zebrafish in early development stage.