一种基于蚯蚓学习行为的神经毒性实验方法研究

An Experimental Method of Neurotoxicity Based on Earthworm Learning Behavior

土壤生物的学习行为是一种综合性的神经高级活动,对土壤中的神经毒性污染物生态风险监测具有重要价值。本研究设计了一套试验装置,基于蚯蚓对白光刺激的厌恶本性,通过振动-白光配对刺激,对蚯蚓进行学习训练,使蚯蚓领会借助加速移动阻止白光刺激的策略,通过蚯蚓到达移动位移阈值的时间测定,对蚯蚓的学习行为进行测试,建立了蚯蚓的学习行为测试方法。采用建立的测试方法,对土壤中东莨菪碱和毒死蜱诱导下蚯蚓的学习行为进行了测试,结果表明,1~3 mg·kg^(-1)东莨菪碱与4~12 mg·kg^(-1)毒死蜱污染处理均对蚯蚓的学习能力造成了损伤,污染浓度越高,蚯蚓的学习能力损伤越严重。该测试方法可以快速有效地检测土壤污染导致的蚯蚓学习行为变化,有望用于低浓度神经毒性农药污染土壤的神经毒性快速诊断。

The learning behavior of soil organisms is a kind of comprehensive neural higher activity,which is of great value to the ecological risk monitoring of neurotoxic pollutants in soil.In order to establish learning behavior test method of earthworm,a set of test apparatus was designed in this paper based on earthworm’dislike of white light stimulation.Earthworms were trained to understand the strategy of preventing white light stimulation with fast moving through the vibration-white light pairing stimulus.Earthworm learning behavior was tested by determination of the time of earthworm arriving movement displacement threshold.Using the established test method,earthworms’learning behavior was tested under the influence of scopolamine and chlorpyrifos in soil.The results showed that the learning ability of earthworms was damaged by 1~3 mg·kg^(-1) scopolamine and 4~12 mg·kg^(-1) chlorpyrifos in soil.The higher the pollution concentration was,the more serious the learning ability of earthworms was damaged.This test method could quickly and effectively detect the change of earthworm learning behavior caused by soil pollution,and was expected to be used for the rapid diagnosis of neurotoxicity of low-concentration neurotoxic pesticides in contaminated soil.