During the last decades, depression has been diagnosed in increasing numbers, accompanied by rising prescription rates of antidepressants. Concomitantly, these pharmaceuticals are frequently detected in surface waters. Serotonin and noradrenalin reuptake inhibitors such as venlafaxine form the second largest group of antidepressants worldwide, and venlafaxine is the second most prescribed antidepressant in Germany. As drug targets are evolutionary highly conserved, venlafaxine can potentially change not only behavior and related physiological processes in humans but also in non-target species, especially aquatic organisms. In order to test this hypothesis for fish, we exposed brown trout larvae and juveniles to venlafaxine at concentrations ranging from 1 to 1,000 μg/L. Larvae were exposed for 5 months from the eyed ova stage until 8 weeks post yolk-sac consumption at 7 and 11 °C. Juveniles were exposed for 4 weeks at 7 °C. Mortality, weight, length, behavior during exposure and behavior in a stressful environment were recorded in both experiments. For larvae, additionally, hatching rate and heart rate were analyzed. In juvenile fish, tissue cortisol levels were determined. Our results clearly showed, that brown trout, irrespective of their life stage, change their behavior when being exposed to venlafaxine: During exposure, venlafaxine at 7 °C caused larvae to sojourn in the upper part of the aquaria for a longer time, with a lowest observed effect concentration of 100 μg/L. In a stressful environment with limited space, fish exposed to ≥10 μg/L venlafaxine were less active than controls. Furthermore, venlafaxine reduced the growth of larvae (length at ≥10 μg/L, weight at 1 mg/L) and their survival after 5 months (at 1 mg/L). Hatching rate and heart rate of larvae as well as tissue cortisol concentration of juveniles were not affected by venlafaxine treatment.

中文翻译：

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暴露于抗抑郁药文拉法辛后褐鳟的行为和发育变化

在过去的几十年里，越来越多的人诊断出抑郁症，同时抗抑郁药的处方率也在上升。同时，经常在地表水中检测到这些药物。血清素和去甲肾上腺素再摄取抑制剂（如文拉法辛）构成了全球第二大抗抑郁药组，文拉法辛是德国第二大处方抗抑郁药。由于药物靶点在进化上高度保守，文拉法辛不仅可以改变人类的行为和相关生理过程，还可以改变非目标物种，尤其是水生生物的行为和相关生理过程。为了验证鱼类的这一假设，我们将褐鳟鱼幼体和幼体暴露于浓度范围为 1 至 1,000 μg/L 的文拉法辛。幼虫从眼卵期到卵黄囊消耗后 8 周在 7°C 和 11°C 下暴露 5 个月。幼鱼在 7°C 下暴露 4 周。两个实验都记录了死亡率、体重、身长、暴露期间的行为和压力环境中的行为。此外，还分析了幼虫的孵化率和心率。在幼鱼中，测定了组织皮质醇水平。我们的结果清楚地表明，褐鳟，无论它们的生命阶段如何，在接触文拉法辛时都会改变它们的行为：在暴露期间，7°C 的文拉法辛会导致幼虫在水族箱上部逗留更长时间，观察到的最低效应浓度为 100 μg/L。在空间有限的压力环境中，暴露于≥10 μg/L 文拉法辛的鱼的活跃度低于对照组。此外，文拉法辛降低了幼虫的生长（长度≥10 μg/L，体重 1 mg/L）及其 5 个月后的存活率（1 mg/L）。文拉法辛处理不影响幼虫的孵化率和心率以及幼虫的组织皮质醇浓度。