Analysis of the neurotoxic effects of neuropathic organophosphorus compounds in adult zebrafish

Inhibition and aging of neuropathy target esterase (NTE) by exposure to neuropathic organophosphorus compounds (OPs) can result in OP-induced delayed neuropathy (OPIDN). In the present study we aimed to build a model of OPIDN in adult zebrafish. First, inhibition and aging of zebrafish NTE activity were characterized in the brain by using the prototypic neuropathic compounds cresyl saligenin phosphate (CBDP) and diisopropylphosphorofluoridate (DFP). Our results show that, as in other animal models, zebrafish NTE is inhibited and aged by both neuropathic OPs. Then, a neuropathic concentration inhibiting NTE activity by at least 70% for at least 24 h was selected for each compound to analyze changes in phosphatidylcholines (PCs), lysophosphatidylcholines (LPCs) and glycerolphosphocholine (GPC) profiles. In spite to the strong inhibition of the NTE activity found for both compounds, only a mild increase in the LPCs level was found after 48 h of the exposure to DFP, and no effect were observed by CBDP. Moreover, histopathological evaluation and motor function outcome analyses failed to find any neurological abnormalities in the exposed fish. Thus, our results strongly suggest that zebrafish is not a suitable species for the development of an experimental model of human OPIDN. © 2018 The Author(s).This study was funded by the NATO SfP project MD.SFPP 984777 (D.R.), the European Research Council under European Union’s Seven Framework Programme (FP/2007–2013)/ERC Grant Agreement n. 320737, and the Spanish Government (CTM2017-83242-R; D.R.). M.F. acknowledges the financial support from the Government of Catalonia through a Beatriu de Pinos fellowship (2016 BP-B 00233). I.F. was supported by the Ministry of Economy and Competitivity of Spain (FPI grant BES-2015-075023). The authors thank Mr. Marc Mañas for his valuable assistance building the Open Field Test setup.Peer reviewe