Butyl paraben (BuP) is widely used in cosmetics, drugs, and food preservation. Recently it is an identified new pollutant that affects various aspects of reproduction, lipid metabolism, and nervous system. Behavioral activity serves as a pre-warning biomarker for predicting water quality. So, in this study, the changes in some behaviors and its neurotransmitters and cell apoptosis in the brain of Chinese striped-necked turtles (Mauremys sinensis) were studied when the turtles were exposed to BuP concentrations of 0, 5, 50, 500, and 5000 µg/L for 21 weeks. The results showed that, the basking time and altering scores to external stimuli in the groups of 50, 500, and 5000 µg/L were significantly reduced, while the time for body-righting was significantly increased, compared with the control (0 µg/L), indicating that the turtles exhibited depression and inactive behavior. The analysis of neurotransmitter in the brain showed that 5-hydroxytryptamine (5-HT) contents in the groups of 500 and 5000 µg/L were significantly higher than the other groups, which was due to an increase in the mRNA relative expression levels of the 5-HT receptor gene (5-HTR), neurotransmitter transporter genes (Drd4, Slc6a4), and neurotransmitter synthase tryptophan hydroxylase (TPH). Furthermore, GABA transaminase (GABA-T) activity increased in the 500 and 5000 µg/L groups, and tyrosine hydroxylase (TH) activity increased dramatically in the 5000 µg/L group. However, acetyl-CoA (AChE) activity was significantly reduced in these four BuP exposure groups. These changes could be attributed to decreased movement velocity and increased inactivity. Meanwhile, the mRNA expression level of BAX, Bcl-2, caspase-9 and TUNEL assay indicated the occurrence of cell apoptosis in the brains of the higher BuP exposed groups, which may play an important role in neuronal death inducing behavior change. In summary, these findings offer fundamental insights into turtle ecotoxicology and serve as a foundation for a comprehensive assessment of the ecological and health risks associated with BuP.

对羟基苯甲酸丁酯（BuP）广泛用于化妆品、药物和食品保存。最近它是一种新的污染物，会影响生殖、脂质代谢和神经系统的各个方面。行为活动可作为预测水质的预警生物标志物。因此，本研究研究了中华斑鳖（Mauremys sinensis）在0、5、50、500、500浓度的BuP浓度下，其某些行为及其神经递质和脑细胞凋亡的变化。 5000 µg/L，持续 21 周。结果表明，与对照组（0μg/L）相比，50、500、5000μg/L组的晒太阳时间和对外界刺激的改变分数显着减少，而翻身时间显着增加。 L)，表明海龟表现出抑郁和不活跃的行为。脑内神经递质分析显示，500、5000μg/L组5-羟色胺（5-HT）含量显着高于其他组，这是由于脑内神经递质mRNA相对表达水平增加所致。 5-HT 受体基因 (5-HTR)、神经递质转运蛋白基因 (Drd4、Slc6a4) 和神经递质合酶色氨酸羟化酶 (TPH)。此外，500和5000 µg/L组的GABA转氨酶（GABA-T）活性增加，5000 µg/L组的酪氨酸羟化酶（TH）活性显着增加。然而，这四个 BuP 暴露组的乙酰辅酶 A (AChE) 活性显着降低。这些变化可能归因于运动速度降低和不活动增加。同时，BAX、Bcl-2、caspase-9的mRNA表达水平和TUNEL检测表明高BuP暴露组脑内细胞凋亡的发生，这可能在神经元死亡诱导行为改变中发挥重要作用。总之，这些发现为海龟生态毒理学提供了基本见解，并为全面评估与 BuP 相关的生态和健康风险奠定了基础。