Christian Marcelo, Kraft Michelle, Wilknitz Paul, Nowotny Manuela, Schöneich Stefan
Institute for Zoology and Evolutionary Research, Friedrich Schiller University Jena, Erbertstraße 1, 07743, Jena, Germany.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2025 May;211(3):311-325. doi: 10.1007/s00359-025-01735-8. Epub 2025 Feb 13.
Since the EU banned classic neonicotinoids like imidacloprid and clothianidin, they may be replaced by more recently marketed insecticides such as flupyradifurone. However, they all operate on the same neuropharmacological principle as selective agonists at the insect's nicotinic acetylcholine receptors. Here we investigated the impact of flupyradifurone, imidacloprid and clothianidin on the neuronal processing in the auditory pathway of the desert locust Schistocerca gregaria. While stepwise increasing the insecticide concentration in the haemolymph, we extracellularly recorded the spike responses of auditory afferents in the tympanal nerve and of auditory interneurons in the neck connectives. All three insecticides showed a very similar dose-dependent suppression of spike responses in the auditory interneurons ascending towards the brain, whereas the spike responses in the sensory neurons of the ears appeared unaffected. Furthermore, by systematic injection experiments we demonstrate that insecticide dosages which already supress the information transfer in the auditory pathway are by far too low to induce the typical poisoning symptoms like trembling, spasms, and paralysis. We discuss how sublethal intoxication with classical neonicotinoids or functionally related insecticides like flupyradifurone may disrupt the postsynaptic balance between excitation and inhibition in the auditory pathway of locusts and other orthopteran insects.
自欧盟禁止使用吡虫啉和噻虫胺等经典新烟碱类杀虫剂以来，它们可能会被氟吡呋喃酮等最近上市的杀虫剂所取代。然而，它们都以相同的神经药理学原理发挥作用，即作为昆虫烟碱型乙酰胆碱受体的选择性激动剂。在此，我们研究了氟吡呋喃酮、吡虫啉和噻虫胺对沙漠蝗（Schistocerca gregaria）听觉通路中神经元处理过程的影响。在逐步提高血淋巴中杀虫剂浓度的同时，我们在细胞外记录了鼓膜神经中听觉传入神经元以及颈部神经索中听觉中间神经元的锋电位反应。所有这三种杀虫剂对向脑内上行的听觉中间神经元的锋电位反应均表现出非常相似的剂量依赖性抑制，而耳内感觉神经元的锋电位反应似乎未受影响。此外，通过系统性注射实验我们证明，那些已经抑制听觉通路中信息传递的杀虫剂剂量，远低于诱发颤抖、痉挛和麻痹等典型中毒症状所需的剂量。我们讨论了经典新烟碱类杀虫剂或与氟吡呋喃酮功能相关的杀虫剂的亚致死中毒可能如何破坏蝗虫和其他直翅目昆虫听觉通路中突触后兴奋与抑制之间的平衡。
