Accumulating evidence suggests that cyanotoxins can exert neurotoxic effects on exposed aquatic organisms but most studies have focused on purified toxins rather than on the more complex effects of cyanobacterial blooms. To evaluate this issue in an environmentally relevant model, we assessed the developmental neurotoxicity induced by Microcystis aeruginosa on newly hatched zebrafish. After four days of exposure, the locomotor activity of zebrafish larvae was significantly decreased with increasing algae concentration. The levels of both acetylcholinesterase (AChE) and dopamine (DA) were decreased, accompanied by a decline in ache, chrna7 and manf and a compensatory increase in nr4a2b transcription. Furthermore, the expression of nine marker genes for nervous system function or development, namely, elavl3, gap43, gfap, mbp, nestin, ngn1, nkx2.2a, shha and syn2a, similarly decreased after algal exposure. These results demonstrated that Microcystis aeruginosa exposure affected cholinergic and dopaminergic neurotransmitter systems, the transcription of key nervous system genes, and consequently the activity level of larval zebrafish. Importantly, discrepancies in the neurotoxic effects observed in this study and in previous reports that were based on exposure to pure cyanotoxin highlight the necessity for further investigation of cyanobacterial bloom mixtures when assessing the ecotoxicity of cyanobacteria.

越来越多的证据表明，蓝藻毒素可以对裸露的水生生物产生神经毒性作用，但大多数研究都集中在纯化毒素上，而不是蓝藻水华的更为复杂的作用上。为了在与环境相关的模型中评估此问题，我们评估了铜绿微囊藻对新孵化的斑马鱼诱导的发育神经毒性。暴露四天后，随着藻类浓度的增加，斑马鱼幼虫的运动能力显着下降。两个乙酰胆碱酯酶（AChE）和多巴胺（DA）的水平下降，在下降伴有疼痛，CHRNA7和MANF和代偿性增高nr4a2b转录。此外，九个标记基因为神经系统的功能或发展，即，表达elavl3，GAP43，GFAP，MBP，巢蛋白，ngn1，nkx2.2a，shha和syn2a，类似地藻类暴露后下降。这些结果表明铜绿微囊藻暴露会影响胆碱能和多巴胺能神经递质系统，关键神经系统基因的转录，进而影响幼虫斑马鱼的活动水平。重要的是，在这项研究和以前的报告中观察到的基于暴露于纯氰毒素的神经毒性作用方面的差异，突出了在评估蓝细菌的生态毒性时进一步研究蓝细菌水华混合物的必要性。