Psychotropics, especially benzodiazepines, are commonly prescribed worldwide. Poorly eliminated at wastewater treatment plants, they belong to a group of emerging contaminants. Due to their interaction with the GABA_A receptor, they may affect the function of the nervous system of non-target organisms, such as aquatic organisms. The toxicity of oxazepam, a very frequently detected benzodiazepine in continental freshwater, has been largely studied in aquatic vertebrates over the last decade. However, its effects on freshwater non-vertebrates have received much less attention. We aimed to evaluate the long-term effects of oxazepam on the juvenile stage of a freshwater gastropod widespread in Europe, Radix balthica. Juveniles were exposed for a month to environmentally-relevant concentrations of oxazepam found in rivers (0.8 μg/L) and effluents (10 μg/L). Three main physiological functions were studied: feeding, growth, and locomotion. Additionally, gene expression analysis was performed to provide insights into toxicity mechanisms. There was a strong short-term activation of the feeding rate at low concentration, whereas the high dose resulted in long-term inhibition of food intake. A significant decrease in mortality rate was observed in juveniles exposed to the lowest dose. Shell growth and locomotor activity did not appear to be affected by oxazepam. Transcriptomic analysis revealed global over-expression of genes involved in the nervous regulation of the feeding, digestive, and locomotion systems after oxazepam exposure. The molecular analysis also revealed a possible interference of animal manipulation with the molecular effects induced by oxazepam exposure. Overall, these results improve our understanding of the effects of the psychoactive drug oxazepam on an aquatic mollusc gastropod.

精神药物，特别是苯二氮卓类药物，在世界范围内普遍使用。在废水处理厂中几乎没有消除，它们属于一组新兴污染物。由于它们与GABA _A受体的相互作用，它们可能会影响非目标生物（例如水生生物）的神经系统功能。在过去的十年中，在水生脊椎动物中大量研究了奥沙西m的毒性，奥沙西m是一种在大陆淡水中非常常见的苯二氮卓类。但是，它对淡水非脊椎动物的影响受到的关注要少得多。我们旨在评估奥沙西m对欧洲广泛分布的淡水腹足纲幼虫的幼年期的长期影响。将少年暴露于河流（0.8μg/ L）和废水（10μg/ L）中与环境有关的奥沙西m浓度下暴露一个月。研究了三种主要的生理功能：进食，生长和运动。另外，进行基因表达分析以提供对毒性机制的见解。在低浓度下，短期内会强烈刺激进食速度，而高剂量会长期抑制食物摄入。暴露于最低剂量的未成年人的死亡率显着降低。壳生长和运动活性似乎不受奥沙西m的影响。转录组学分析揭示了奥沙西m暴露后参与进食，消化和运动系统神经调节的基因的整体过表达。分子分析还表明，动物操作可能会受到奥沙西m暴露引起的分子效应的干扰。总体而言，这些结果增进了我们对精神活性药物奥沙西m对水生软体动物腹足动物的影响的理解。