采用Noldus视频跟踪系统分析早期氯胺酮暴露对成鱼学习记忆功能的影响

An analysis of the effects of early ketamine exposure on the learning and memory of adult zebrafish using the Noldus visual tracking system

目的 采用Noldus视频跟踪系统结合T迷宫装置建立斑马鱼学习记忆模型，分析早期氯胺酮（Ket）暴露对斑马鱼成鱼学习记忆的影响。方法 实验随机分5组，Control组（E3孵化液）与4组不同剂量氯胺酮暴露组（Ket 0.2，Ket 0.4，Ket 0.8和Ket 1.6 g/L 组）；氯胺酮暴露组给予4 hpf（hours post fertilization, hpf）斑马鱼胚胎不同浓度氯胺酮持续暴露14 h，待饲养至成鱼采用Noldus视频跟踪系统结合T迷宫进行斑马鱼轨迹实时记录并评价学习记忆能力；其中迷宫左臂连接1个富营养区（enriched chamber，EC），每天测试1次，共测试5次，实时记录各组斑马鱼游动轨迹及分析进入EC区的潜伏时间。结果 斑马鱼经过5次训练后，测试第5次与第1次相比，Control组斑马鱼进入EC区的潜伏时间明显缩短（P〈0.05），而氯胺酮暴露组斑马鱼进入EC区的潜伏时间无明显缩短。结论 利用Noldus视频跟踪系统结合T迷宫建立的斑马鱼学习记忆模型可以较好地评估斑马鱼成鱼的学习记忆功能；胚胎发育早期氯胺酮暴露会导致斑马鱼成鱼阶段的学习记忆功能损害。

Objective To analyze the effects of early ketamine exposure on the learning and memory of adult zebrafish using the Noldus visual tracking system combined with T maze. Methods Zebrafish were randomly divided into five groups： a control group （using E3 solution） and ketamine （Ket） exposure groups （at the doses of 0.2, 0.4, 0.8 and 1.6 g/L Ket）. The 4 hpf （hours post fertilization） zebrafish embryos in Ket exposure groups were exposed to different concentrations of ketamine for 14 h. When the embryos grew up to adult zebrafish, their trace was recorded, while their learning and memory was evaluated using the Noldus video tracking system combined with T maze. The maze was equipped with an enriched chamber （EC） on the left arm. The behavior of zebrafish was examined once per day for a total of five times. The swimming trace and the latency to enter into EC of each group were recorded. Results The zebrafish were trained for five times. Compared with their behavior on the first time, the control group showed remarkably reduced latency to enter into EC on the fifth time （P〈0.05）, while no marked decreases in the latency was found in the Ket exposure groups. Conclusions The Noldus visual tracking system combined with T maze is a reliable system to evaluate the learning and memory of adult zebrafish. Embryonic exposure to ketamine can lead to impaired learning and memory of zebrafish in adulthood.