Research Article

Neurotoxic Effects of Chlorpyrifos Exposure in a Zebrafish (Danio rerio) Model: Investigation of Behavioral, Enzymatic and Molecular Responses

Volume: 13 Number: 2 December 24, 2025
TR EN

Neurotoxic Effects of Chlorpyrifos Exposure in a Zebrafish (Danio rerio) Model: Investigation of Behavioral, Enzymatic and Molecular Responses

Abstract

Chlorpyrifos (CPF) is a widely used insecticide that has been shown to affect neurobehavioral development. Exposure to CPF during development causes neurobehavioral and neurotoxic effects. In this study, zebrafish larvae were acutely exposed to 0.01 μg/ml and 0.1 μg/ml CPF and its effect on circadian rhythm and anxiety was tested by molecular and behavioral analyses. Analysis of the results showed that CPF exposure altered the transcription levels of genes associated with neurodevelopment (Bdnf), circadian rhythm (Bmal1, Per), phototransduction (Gnat2) and stress response (Crhr, 5ht4). Furthermore, CPF was found to inhibit acetylcholinesterase (AChE) enzyme activity and gene expression levels in a dose-dependent manner. In addition, CPF caused disruptions in locomotor activity, and behavioral responses were observed, especially depending on the circadian phase. Moreover, anxiety-related behavioral parameters (e.g. tigmotaxis) were increased and these behavioral findings were supported at the molecular level. These results demonstrate that the neurotoxic effects of chlorpyrifos occur at both behavioral and genetic levels and highlight the potential risks of environmental pesticide exposure on the development of the nervous system of aquatic vertebrates. Keywords: Chlorpyrifos, zebrafish, circadian rhythm, anxiety

Keywords

Ethical Statement

The study was terminated at 96 h after spawning, and since zebrafish larvae less than 120 h were used, ethics committee approval was not required under the European Union Directives on the Protection of Animals (86/609/EEC and 2010/63/EU).

References

  1. [1] K. D. Racke, “Environmental Fate of Chlorpyrifos,” 1993, pp. 1–150. doi: 10.1007/978-1-4612-4362-5_1.
  2. [2] M. H. Fulton and P. B. Key, “ACETYLCHOLINESTERASE INHIBITION IN ESTUARINE FISH AND INVERTEBRATES AS AN INDICATOR OF ORGANOPHOSPHORUS INSECTICIDE EXPOSURE AND EFFECTS,” Environ Toxicol Chem, vol. 20, no. 1, p. 37, 2001, doi: 10.1897/1551-5028(2001)020<0037:AIIEFA>2.0.CO;2.
  3. [3] D. L. Eaton et al., “Review of the Toxicology of Chlorpyrifos With an Emphasis on Human Exposure and Neurodevelopment,” Crit Rev Toxicol, vol. 38, no. sup2, pp. 1–125, Jan. 2008, doi: 10.1080/10408440802272158.
  4. [4] K. Howe et al., “The zebrafish reference genome sequence and its relationship to the human genome,” Nature, vol. 496, no. 7446, pp. 498–503, Apr. 2013, doi: 10.1038/nature12111.
  5. [5] A. V. Kalueff, A. M. Stewart, and R. Gerlai, “Zebrafish as an emerging model for studying complex brain disorders,” Trends Pharmacol Sci, vol. 35, no. 2, pp. 63–75, Feb. 2014, doi: 10.1016/j.tips.2013.12.002.
  6. [6] H. Richendrfer, S. D. Pelkowski, R. M. Colwill, and R. Créton, “Developmental sub-chronic exposure to chlorpyrifos reduces anxiety-related behavior in zebrafish larvae,” Neurotoxicol Teratol, vol. 34, no. 4, pp. 458–465, Jul. 2012, doi: 10.1016/j.ntt.2012.04.010.
  7. [7] D. Yang et al., “Chlorpyrifos-Oxon Disrupts Zebrafish Axonal Growth and Motor Behavior,” Toxicological Sciences, vol. 121, no. 1, pp. 146–159, May 2011, doi: 10.1093/toxsci/kfr028.
  8. [8] E. D. Levin, H. A. Swain, S. Donerly, and E. Linney, “Developmental chlorpyrifos effects on hatchling zebrafish swimming behavior,” Neurotoxicol Teratol, vol. 26, no. 6, pp. 719–723, Nov. 2004, doi: 10.1016/j.ntt.2004.06.013.

Details

Primary Language

English

Subjects

Animal Behaviour

Journal Section

Research Article

Early Pub Date

December 24, 2025

Publication Date

December 24, 2025

Submission Date

July 17, 2025

Acceptance Date

October 1, 2025

Published in Issue

Year 2025 Volume: 13 Number: 2

APA
Sulukan, E. (2025). Neurotoxic Effects of Chlorpyrifos Exposure in a Zebrafish (Danio rerio) Model: Investigation of Behavioral, Enzymatic and Molecular Responses. Mus Alparslan University Journal of Science, 13(2), 318-324. https://doi.org/10.18586/msufbd.1743947
AMA
1.Sulukan E. Neurotoxic Effects of Chlorpyrifos Exposure in a Zebrafish (Danio rerio) Model: Investigation of Behavioral, Enzymatic and Molecular Responses. Mus Alparslan University Journal of Science. 2025;13(2):318-324. doi:10.18586/msufbd.1743947
Chicago
Sulukan, Ekrem. 2025. “Neurotoxic Effects of Chlorpyrifos Exposure in a Zebrafish (Danio Rerio) Model: Investigation of Behavioral, Enzymatic and Molecular Responses”. Mus Alparslan University Journal of Science 13 (2): 318-24. https://doi.org/10.18586/msufbd.1743947.
EndNote
Sulukan E (December 1, 2025) Neurotoxic Effects of Chlorpyrifos Exposure in a Zebrafish (Danio rerio) Model: Investigation of Behavioral, Enzymatic and Molecular Responses. Mus Alparslan University Journal of Science 13 2 318–324.
IEEE
[1]E. Sulukan, “Neurotoxic Effects of Chlorpyrifos Exposure in a Zebrafish (Danio rerio) Model: Investigation of Behavioral, Enzymatic and Molecular Responses”, Mus Alparslan University Journal of Science, vol. 13, no. 2, pp. 318–324, Dec. 2025, doi: 10.18586/msufbd.1743947.
ISNAD
Sulukan, Ekrem. “Neurotoxic Effects of Chlorpyrifos Exposure in a Zebrafish (Danio Rerio) Model: Investigation of Behavioral, Enzymatic and Molecular Responses”. Mus Alparslan University Journal of Science 13/2 (December 1, 2025): 318-324. https://doi.org/10.18586/msufbd.1743947.
JAMA
1.Sulukan E. Neurotoxic Effects of Chlorpyrifos Exposure in a Zebrafish (Danio rerio) Model: Investigation of Behavioral, Enzymatic and Molecular Responses. Mus Alparslan University Journal of Science. 2025;13:318–324.
MLA
Sulukan, Ekrem. “Neurotoxic Effects of Chlorpyrifos Exposure in a Zebrafish (Danio Rerio) Model: Investigation of Behavioral, Enzymatic and Molecular Responses”. Mus Alparslan University Journal of Science, vol. 13, no. 2, Dec. 2025, pp. 318-24, doi:10.18586/msufbd.1743947.
Vancouver
1.Ekrem Sulukan. Neurotoxic Effects of Chlorpyrifos Exposure in a Zebrafish (Danio rerio) Model: Investigation of Behavioral, Enzymatic and Molecular Responses. Mus Alparslan University Journal of Science. 2025 Dec. 1;13(2):318-24. doi:10.18586/msufbd.1743947