摘要
应用电生理方法研究了除草剂草甘膦对中华大蟾蜍（Bufo gargarizans Cantor）坐骨神经干冲动产生和传导的影响。用不同浓度的草甘膦溶液对中华大蟾蜍进行胁迫处理,草甘膦有效成分经由皮肤进入蟾蜍体内而作用于神经系统,利用生物信号采集处理系统测定草甘膦胁迫下中华大蟾蜍离体坐骨神经干的应激反应时间、动作电位幅度和冲动传导速度,结果表明：随着草甘膦溶液浓度的升高,中华大蟾蜍坐骨神经干接受刺激后产生冲动所需的时间逐渐延长,动作电位峰值降低,神经冲动传导速度亦逐渐减慢。草甘膦施用后,中华大蟾蜍7d内的平均应激反应时间与草甘膦浓度呈正相关,而动作电位幅度及传导速度均与草甘膦浓度呈负相关。草甘膦溶液浓度达到推荐农田使用浓度1.64~2.87ml/L时,各处理组蟾蜍的应激反应时间、动作电位幅度和冲动传导速度均与对照组差异极显著（P〈0.01）。同时,随着试验处理时间的延长,中华大蟾蜍神经干对刺激的反应变得更为迟钝,神经冲动的传导速度也进一步减慢。回归分析可知,中华大蟾蜍坐骨神经干的应激反应时间与草甘膦施用后天数呈正相关,而神经传导速度与药后天数呈负相关。由此可以说明,草甘膦胁迫条件下,中华大蟾蜍神经细胞对刺激反应的灵敏性降低，动作电位的产生及传导受到一定程度的抑制和阻碍。
Using the electrophysiological method, this paper studied the influences of glyphosate on the nerve impulse generation and conduction of nerve trunk of Bufo gargarizans Cantor. By spraying a glyphosate solution on the toads＇ skin, the valid ingredient of glyphosate can penetrate the toads＇ bodies and act on their nervous systems. The biological signal recording and processing system was applied to measure the reaction time, the active potential peak value and the impulse performance parameters of the nerve trunk, including the conduction velocity. The results showed that with increasing glyphosate concentration, the reaction time of the nerve trunk got longer, but the peak value of active potential decreased and the velocity of the impulse conduction slowed down. For seven days after being sprayed with glyphosate solution, test toads＇ the average reaction time was positively correlated with the spray solution glyphosate concentration. The active potential peak value and impulse conduction velocity were, however, negatively correlated with glyphosate concentration. When Bufo gargarizans were exposed to the ghyphosate solutions in dilutions of 1.64, 2.05, 2.87ml/L, （ which are the recommended concentrations for killing field weeds, ） the reaction time, active potential peak value and impulse conduction velocity of the tested groups were all statistically different from those of the control group. Meanwhile, the testing time （days after spraying the glyphosate solutions ） also affected the action potential generation and conduction of the nerve trunk. The reaction time of the nerve trunk was positively correlated with testing time. However, the relationship between the impulse conduction velocity and the testing time was negative. It can be concluded that the application of glyphosate will decrease the sensitivity of the nerve trunk and also hamper the impulse generation and conduction of Bufo gargarizans.
出处
《生态学报》
CAS
CSCD
北大核心
2007年第3期1177-1184,共8页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目(No30660038)
井冈山学院校级基金资助项目~~
关键词
草甘膦
坐骨神经
动作电位
神经传导
中华大蟾蜍
Glyphosate
nerve trunk
action potential
impulse conduction
Bufo gargarizans
