The insecticide pymetrozine selectively affects chordotonal mechanoreceptors
The insecticide pymetrozine selectively affects chordotonal mechanoreceptors
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DOI：
10.1242/jeb.01917
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发表时间：
2005-12-01
影响因子：
2.8
通讯作者：
Kayser, H
中科院分区：
文献类型：
--
作者：
Ausborn, J;Wolf, H;Kayser, H
吡蚜酮是一种神经活性杀虫剂，但其在神经系统中的作用部位尚不清楚。根据之前对蝗虫症状的研究，选择控制中腿股骨-胫骨关节的反馈回路来检查杀虫剂的可能目标。监测关节位置和运动的股骨脊索器官是吡蚜酮作用的主要部位，而中间神经元、运动神经元和中央运动控制电路一般对杀虫剂没有明显反应。与翼铰链牵张感受器和背盖相关的脊索器官受到吡蚜酮的影响，其方式与股骨脊索器官相同，表明杀虫剂总体上影响脊索感觉器。浓度低至 10(-8) mol l(-1) 的吡蚜酮会导致刺激相关反应的丧失，并引发（暂时）强直放电或完全消除尖峰活动。值得注意的是，吡蚜酮以全有或全无的方式影响脊索器官，这与之前的独立研究一致。其他检查的感觉器官对吡蚜酮没有反应，即胫骨和肋下静脉上的钟形感器、背盖毛感器（I 型感器）和翼铰拉伸感受器（II 型感器）。
Pymetrozine is a neuroactive insecticide but its site of action in the nervous system is unknown. Based on previous studies of symptoms in the locust, the feedback loop controlling the femur-tibia joint of the middle leg was chosen to examine possible targets of the insecticide. The femoral chordotonal organ, which monitors joint position and movement, turned out to be the primary site of pymetrozine action, while interneurons, motoneurons and central motor control circuitry in general did not noticeably respond to the insecticide. The chordotonal organs associated with the wing hinge stretch receptor and the tegula were influenced by pymetrozine in the same way as the femoral chordotonal organ, indicating that the insecticide affects chordotonal sensillae in general. Pymetrozine at concentrations down to 10(-8) mol l(-1) resulted in the loss of stimulus-related responses and either elicited (temporary) tonic discharges or eliminated spike activity altogether. Remarkably, pymetrozine affected the chordotonal organs in an all-or-none fashion, in agreement with previous independent studies. Other examined sense organs did not respond to pymetrozine, namely campaniform sensillae on the tibia and the subcosta vein, hair sensillae of the tegula (type I sensillae), and the wing hinge stretch receptor (type II sensillae).