Global warming due to climate change, as well as freshwater eutrophication caused by anthropogenic activities are responsible, among other factors, for an increasing occurrence of harmful algal blooms (HABs) in aquatic systems. These can lead to the generation of cyanotoxins, secondary metabolites coming from cyanobacteria, producing adverse effects in living organisms including death. This research aims to study the effects that two neurotoxins, anatoxin-a (ATX-a) and saxitoxin (STX), have on living organisms. Once the stability of both compounds in water was determined for a 24 h period using ultra-high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer (UPLC-MS/MS), zebrafish larvae were exposed to different levels of toxins (1 ng L−1, 10 ng L−1, 100 ng L−1 and 1 μg L−1) during 24 h. Behavioral studies including vibrational startle response (VSR), habituation to vibrational stimuli, basal locomotor activity (BLM) and visual motor response (VMR) were performed using Danio Vision system, and neurotransmitters (NTs) from 15-head pools of control and exposed zebrafish larvae were extracted and analyzed by UPLC-MS/MS. Both compounds induced hypolocomotion in the individuals, while 10 and 100 ng L−1 of ATX-a significantly increased methionine (120 % and 126 %, respectively) and glutamate levels (118 % and 129 %, respectively). Saxitoxin enhanced 3-metoxytyramine (3-MT) levels at 1 ng L−1 by 185 %. The findings of this study show that both studied cyanotoxins influence the behavior of zebrafish larvae as well as their metabolism.

中文翻译：

---

分析鱼腥毒素 a 和石房蛤毒素对斑马鱼幼虫的神经毒性作用


除其他因素外，气候变化导致的全球变暖以及人为活动引起的淡水富营养化是导致水生系统中有害藻华 （HAB） 增加的原因。这些会导致蓝藻毒素的产生，蓝藻是来自蓝藻的次生代谢物，对生物体产生不利影响，包括死亡。本研究旨在研究两种神经毒素，即鱼腥毒素-a （ATX-a） 和石房蛤毒素 （STX），对生物体的影响。使用超高效液相色谱法与三重四极杆质谱仪 （UPLC-MS/MS） 联用测定两种化合物在水中的 24 小时稳定性后，斑马鱼幼虫在 24 小时内暴露于不同水平的毒素（1 ng L-1、10 ng L-1、100 ng L-1 和 1 μg L-1）。使用 Danio Vision 系统进行包括振动惊吓反应 （VSR） 、对振动刺激的习惯化、基础运动活动 （BLM） 和视觉运动反应 （VMR） 在内的行为研究，并从 15 头对照和暴露斑马鱼幼虫中提取神经递质 （NTs） 并通过 UPLC-MS/MS 进行分析。两种化合物都诱导了个体的低速运动，而 10 和 100 ng L-1 的 ATX-a 显着增加了蛋氨酸（分别为 120 % 和 126%）和谷氨酸水平（分别为 118 % 和 129 %）。石房蛤毒素将 1 ng L-1 的 3-甲氧基酪胺 （3-MT） 水平提高了 185 %。这项研究的结果表明，两种研究的蓝藻毒素都会影响斑马鱼幼虫的行为及其新陈代谢。