Chronic exposure to bisphenol S is associated with antagonistic neurobehavioral transformation and cleaved caspase 3 induced neurodegeneration in zebrafish brain

Abstract

Bisphenol S (BPS), a widely used bisphenol analogue, has been increasingly detected in aquatic environments, raising concerns about its potential neurotoxic effects. However, the mechanism underlying the neurotoxicity induced by BPS remains elusive. In this context, our present study was aimed to investigate the impact of temporal BPS exposure towards precocious development of neurobehavioral transformation and neurodegeneration in zebrafish brain. Heightened monoamine oxidase (MAO) activity is associated with induction of aggressive behavioural response. In line with earlier report, our findings following mirror biting test advocated that temporal BPS exposure is associated with gradual genesis of aggressive neurobehavioral response and is correlated with augmented MAO activity and downregulation of tyrosine hydroxylase (TH) expression in zebrafish brain. Our further observation towards native neurobehavioral response as regulated by periventricular grey zone (PGZ) of optic tectum (TeO) of brain showed that duration dependent exposure to BPS is associated with gross transformation in scototaxis and explorative behaviour of zebrafish. Concurrently, our objective was also predestined to emphasize the detrimental effect of BPS on brain biochemistry and neuromorphology. In this line, our findings showed that BPS-persuaded heightened oxidative stress is linked with augmented chromatin condensation and apoptotic cell death as depicted through cleaved caspase-3 expression in zebrafish brain. To understand neuromorphological integrity of PGZ region through expression of NeuN, our findings advocated a significant downregulation following temporal exposure to BPS. In a nutshell, the gross observation delineates the strong neurodegenerative potential of BPS coupled through neurobehavioral transformation, oxidative stress and neuromorphological alteration in zebrafish brain.