Ocular Accumulation of Psychoactive Drugs in Fish: Neurotransmitter Alterations and Potential Implications for Vision

Psychoactive drugs are pervasive in aquatic environments and can adversely affect aquatic life by acting on neurotransmitters, which are present in both humans and fish. Given the role of neurotransmitters in ocular functions, their alteration may impair vision. We exposed European perch to psychoactive drug mixtures under laboratory and natural conditions. Comprehensive analyses of drug accumulation in fish brains and eyes, along with changes in neurotransmitter levels, were conducted. Results showed that psychoactive drugs accumulated more in the eyes than in the brain, significantly altering neurotransmitter concentrations. This study suggests that focusing solely on behavioral endpoints and brain effects may be insufficient for risk assessment, as vision impairment due to ocular drug accumulation is also a concern.