Impact of Psychoactive Pollutants on Neurotransmitters and Reproductive Health in European Perch (Perca fluviatilis)

Psychoactive compounds (PSYCs) are emerging aquatic pollutants. Due to the evolutionary conservation of neurotransmitters and receptors, PSYCs have the potential to adversely affect non-target organisms. There is a research gap in understanding their impact on fish reproduction, which is regulated by neurotransmitters through the hypothalamic-pituitary-gonadal axis. This study investigated the impact of environmentally relevant concentrations of a mixture of seven PSYCs (citalopram, donepezil, gabapentin, methamphetamine, sertraline, tramadol, and venlafaxine) on European perch (Perca fluviatilis), focusing on neurotransmitter levels in the brain, gonads, and sperm, along with bioaccumulation, histopathology, and sperm quality. The LC-HRMS/MS was used to analyze PSYCs and neurotransmitters. Gonad and sperm samples were subjected to microscopic analysis. Sertraline exhibited the highest concentrations in brains (7.8 ± 2.3 µg/g-d.w.), gonads (5.7 ± 1.8 µg/g-d.w.), and sperm (1.1 ± 0.25 µg/g-d.w.) after 23-days of exposure, followed by norsertraline, donepezil, citalopram, tramadol, methamphetamine, and venlafaxine. Their concentrations were significantly higher in the brain and gonads compared to sperm (ANOVA; p < 0.05). Bioaccumulation increased significantly over time (ANOVA; p < 0.05). Exposure to PSYCs and temporal factors significantly altered neurotransmitter levels in the brain, gonads, and sperm. The exposure caused significant fluctuations in correlation patterns between neurotransmitters, with each experimental group showing unique variations at specific time points throughout the study (Spearman rs; p < 0. 05). However, gonad parameters, microanatomy, and sperm quality parameters were not affected by the PSYCs. This pioneering research underscores the potential risk of exposure to environmental concentrations of PSYCs to fish health and reproduction.