Environmental Toxicology Graduate Program, University of California, Riverside, CA 92521, USA.
Toxicon. 2012 Feb;59(2):320-8. doi: 10.1016/j.toxicon.2011.10.011. Epub 2011 Nov 7.
The emerald jewel wasp, Ampulex compressa, exploits the American cockroach, Periplaneta americana, as a host for its progeny. The wasp subdues the host by stinging directly into the brain and subesophageal ganglion, inducing long-term hypokinesia. The hypokinesic host lacks normal escape behavior and motivation to walk, making it easy for subjugation by the wasp. The mechanism underlying hypokinesia induction is not known, but depletion of monoamines induces behavior resembling venom-induced hypokinesia. To test whether amine depletion occurs in stung animals, we used high-performance liquid chromatography with electrochemical detection (HPLC-ED) to measure quantitatively amine levels in the central nervous system. Our data show clearly that levels of dopamine, serotonin, octopamine and tyramine remain unchanged in stung animals, whereas animals treated with reserpine exhibited marked depletion of all amines sampled. Furthermore, stung animals treated with reserpine show depletion of amines, demonstrating that envenomation also does not interfere with amine release. These results show that hypokinesia induced by Ampulex venom does not result from amine depletion or inability to release monoamines in the central nervous system.
翡翠宝石黄蜂，Ampulex compressa，利用美洲大蠊，Periplaneta americana，作为其后代的宿主。黄蜂通过直接刺向大脑和食管下神经节来制服宿主，从而诱导长期的运动机能减退。运动机能减退的宿主缺乏正常的逃避行为和行走的动力，因此很容易被黄蜂制服。运动机能减退诱导的机制尚不清楚，但单胺类物质的耗竭会引起类似于毒液诱导的运动机能减退的行为。为了测试被蜇动物是否发生胺耗竭，我们使用高效液相色谱电化学检测（HPLC-ED）定量测量中枢神经系统中的胺类物质水平。我们的数据清楚地表明，被蜇动物的多巴胺、血清素、章鱼胺和酪胺水平保持不变，而用利血平处理的动物表现出所有被采样胺类物质的明显耗竭。此外，用利血平处理被蜇的动物表现出胺类物质的耗竭，表明毒液也不会干扰单胺类物质的释放。这些结果表明，Ampulex 毒液诱导的运动机能减退不是由于中枢神经系统中单胺类物质的耗竭或不能释放引起的。
