Effects of chlorpyrifos toxicity on brain, pseudobranchial neurosecretory system and swimming performance of a catfish, Heteropneustes fossilis

Abstract

In the present study, it was aimed to evaluate the adverse effects of CPF on the histopathology of the optic tectum and cerebellum, pseudobranchial neurosecretory system (PNS), biochemical assays of brain tissue, and locomotory behavior in catfish, Heteropneustes fossilis. The fishes were exposed to an environmentally relevant concentration of 0.09 and 0.192 mg/L of CPF for 7, 15, and 30 d. The CPF toxicity induced degenerative changes with significantly decreased cell size, number, and nucleo-cytoplasmic (N/C) ratio of the PNS; and altered neuro-architectural pattern of optic tectum with degenerative changes in mononuclear and granular cells and necrotic variation in granular and Purkinje cells of the cerebellum. The Acetylcholinesterase (AChE) and Catalase (CAT) activity in the CPF-exposed brain was significantly decreased, whereas Superoxide dismutase (SOD) and Malondialdehyde (MDA) level was significantly increased in comparison with control. In CPF-exposed fishes, the respiratory movements and locomotory behavioral pattern like swimming speed, total distance traveled, time mobile, absolute turn angle, head: distance traveled, maximum speed were significantly decreased, whereas time immobile and time freezing episodes were significantly increased as compared to control fishes. The present study concludes that environmentally relevant concentration of CPF may induce histopathological, biochemical, physiological, and behavioral disturbances in a non-target organism, H. fossilis.

Graphical Abstract

Keywords:

• Chlorpyrifos
• pseudobranchial neurosecretory system
• fish brain
• locomotor activity
• AChE
• oxidative stress
• H. fossilis

Acknowledgements

The authors are grateful to the Head, Department of Zoology, University of Allahabad, Prayagraj, India, for providing laboratory facilities and Botanical Survey of India (BSI), Prayagraj for photographic facilities.

Authors contributions

Ajeet Kr. Mishra: Investigation, writing original draft. Anita Gopesh: Conceptualization, critical suggestions. K. P. Singh: Conceptualization, critical suggestions, critical review of manuscript.

Disclosure statement

No conflict of interest was reported by the authors.

Data availability statement

All supportive data are available in the supplementary material.

Additional information

Funding

This work was supported by University Grant Commision, India [DS15/57]