Programa de Pós-graduação em Bioquímica Toxicológica, Universidade Federal de Santa Maria, Avenida Roraima, 1000, Santa Maria, RS 97105-900, Brazil.
Programa de Pós-graduação em Bioquímica Toxicológica, Universidade Federal de Santa Maria, Avenida Roraima, 1000, Santa Maria, RS 97105-900, Brazil.
Environ Toxicol Pharmacol. 2022 Jul;93:103870. doi: 10.1016/j.etap.2022.103870. Epub 2022 May 4.
Manganese (Mn) is an essential metal for living organisms. However, the excess of Mn can be toxic, especially for the central nervous system. Herein, we used adult zebrafish as model organism to investigate the relationship of an environmentally relevant Mn exposure with the onset of neurobehavioral disturbances and brain biochemical alterations. Fish were exposed to MnCl at 0.5, 2.0, 7.5 and 15.0 mg/L for 96 h, and after submitted to trials for examining exploratory, locomotor and anxiety-related behaviors. The neurobehavioral parameters were followed by the analyses of cell viability, Mn accumulation and acetylcholinesterase activity in the brain, and whole-body cortisol levels. By Novel tank, Light dark and Social preference test, we found that the exposure to Mn, along with locomotor deficits induced anxiety-like phenotypes in zebrafish. Most of these behavioral changes were evoked by the highest concentrations, which also caused cell viability loss, higher accumulation of Mn and increased AChE activity in the brain, and an increase in the whole-body cortisol content. Our findings demonstrated that zebrafish are quite sensitive to levels of Mn found in the environment, and that the magnitude of the neurotoxic effects may be associated with the levels of manganese accumulated in the brain. Interestingly, we showed that Mn exposure in addition to motor deficits may also cause psychiatric abnormalities, namely anxiety.
锰（Mn）是生物体必需的金属元素。然而，过量的锰可能是有毒的，尤其是对中枢神经系统。在此，我们以成年斑马鱼为模型生物，研究了环境相关锰暴露与神经行为障碍和大脑生化改变发生之间的关系。鱼在 0.5、2.0、7.5 和 15.0 mg/L 的 MnCl 中暴露 96 h，然后进行探索性、运动性和焦虑相关行为的试验。在分析大脑中的细胞活力、锰积累和乙酰胆碱酯酶活性以及全身皮质醇水平之前，研究了神经行为参数。通过新奇鱼缸、明暗和社会偏好测试，我们发现暴露于 Mn 会导致斑马鱼出现运动缺陷和类似焦虑的表型。这些行为变化大部分是由最高浓度引起的，这也导致了大脑中的细胞活力丧失、锰积累增加和乙酰胆碱酯酶活性增加，以及全身皮质醇含量增加。我们的研究结果表明，斑马鱼对环境中发现的锰水平非常敏感，神经毒性效应的严重程度可能与大脑中积累的锰水平有关。有趣的是，我们发现 Mn 暴露除了运动缺陷外，还可能导致精神异常，即焦虑。
