三氯化铝在酸性环境中对斑马鱼幼鱼运动及学习记忆能力的影响

以斑马鱼胚胎和幼鱼为实验对象,探讨三氯化铝(Al Cl3)在酸性环境中对斑马鱼幼鱼运动能力及学习记忆的影响。将受精后6 h(hours post-fertilization)的斑马鱼胚胎分成2个大组,分别为对照组和三氯化铝组,以观察三氯化铝的毒性作用。每一大组又分为中性(pH7.4)、微酸(pH6.4)和酸性(pH5.4)组,以观察酸性环境分别及与三氯化铝的共同毒性作用。分别采用72 hpf斑马鱼幼鱼机械逃避反射实验、144 hpf斑马鱼幼鱼自发运动、168 hpf单一多次光刺激斑马鱼幼鱼实验等探讨在中性、微酸和酸性环境下暴露铝离子对斑马鱼幼鱼运动能力以及学习记忆的影响。结果显示:与中性环境下的三氯化铝组相比,微酸和酸性环境下的三氯化铝组可以使斑马鱼幼鱼机械逃避次数减少(P0.05),平均速度和移动距离下降(P0.001),斑马鱼幼鱼运动轨迹杂乱无章,自发触壁活动减少;单一多次光刺激实验结果发现,微酸和酸性环境下的三氯化铝组使斑马鱼幼鱼到达平台速度的光照次数显著增加且差异具有统计学意义(P0.001)。以上结果说明,三氯化铝在微酸和酸性环境下,能导致斑马鱼幼鱼运动能力及学习记忆能力下降,并且酸度值越小,对斑马鱼幼鱼运动和学习记忆的影响更显著。酸度值与三氯化铝之间存在协同作用,酸性环境可以使三氯化铝毒性增加。

Effects of Aluminum Chloride on the Movement and Learning and Memory Performance of Zebrafish Larvae in Acidic Water Environment

Using zebrafish embryos and larvae as experimental models, the present study aims to explore the effects of aluminum chloride on the movement and learning and memory performance of zebrafish larvae in acidic water environment. The 6 hours post-fertilization (hpf) zebrafish embryos were divided into 2 groups, i.e. controls and aluminum chloride treated groups. Each group was further subdivided into 3 groups with various acidity environment, which were neutral (pH7.4), slightly acidic (pH6.4), acidic (pH5.4) groups. Performance of movement, and learning and memory ability were evaluated by the mechanical escape reflex experiment of 72 hpf zebrafish larvae, the spontaneous movement of 144 hpf zebrafish larvae and single multiple light stimulation of 168 hpf zebrafish larvae. Results showed that there are significantly decreased number of mechanical escape times of zebrafish (P<0.05), decreased mean velocity and total movement distance (P<0.001) in aluminum chloride treated groups in acidic environment compared with those in neutral environment; while the latency of reaching the platform speed in single photon stimulation test increased significantly (P<0.001). The results suggest that aluminum chloride in acidic environment can induce movements, and learning and memory impairments, and the lower of the acidity value, the significant the effects. We conclude that there is a synergistic effect between acidity and aluminum chloride, and an acidic water environment can increase the toxicity of aluminum chloride.