Nicotinic acetylcholine receptors are an important class of excitatory receptors in the central nervous system of arthropods. In the ticks Ixodes ricinus, the functional and pharmacological properties of nicotinic receptors located in their neurons are still unknown. The objective of this study was to characterize the pharmacological properties of tick nicotinic receptors using membrane microtransplantation in Xenopus laevis oocytes and two-electrodes voltage clamp method. The membranes microtransplanted were extracted from the tick synganglion. We found that oocytes microtransplanted with tick synganglion membranes expressed nicotinic acetylcholine receptor subtypes which were activated by acetylcholine (1 mM) and nicotine (1 mM). Currents induced by pressure application of acetylcholine and nicotine were diminished by 10 nM α-bungarotoxin and methyllycaconitine, suggesting that they expressed two subtypes of nicotinic receptors, α-bungarotoxin-sensitive and -insensitive, respectively. In addition, we found that nicotine receptors expressed in the synganglion membranes were poorly sensitive to the neonicotinoid insecticides clothianidin (CLT), imidacloprid (IMI), acetamiprid (ACE) and thiamethoxam (TMX), in agreement with their lack of activity as acaricides. Interestingly, current amplitudes were strongly potentialized in the presence of 1 μM PNU-120596. CLT was more active as an agonist than IMI, TMX and ACE. Finally, we demonstrated that microtransplantation of purified membrane from the tick synganglion can be a valuable tool for the development and screening of compounds targeting tick nicotinic acetylcholine receptor subtypes.

烟碱乙酰胆碱受体是节肢动物中枢神经系统中一类重要的兴奋性受体。在蓖麻蜱中，位于其神经元中的烟碱受体的功能和药理学特性仍然未知。本研究的目的是在非洲爪蟾中使用膜微移植来表征蜱烟碱受体的药理特性。卵母细胞和两电极电压钳法。微移植的膜是从蜱的合成神经节中提取的。我们发现用蜱突触突膜微移植的卵母细胞表达烟碱乙酰胆碱受体亚型，这些亚型被乙酰胆碱 (1 mM) 和尼古丁 (1 mM) 激活。乙酰胆碱和尼古丁的压力施加引起的电流被 10 nM α-金环蛇毒素和甲基卡乌碱减弱，表明它们分别表达了两种烟碱受体亚型，α-金环蛇毒素敏感和不敏感。此外，我们发现在合成神经节膜中表达的尼古丁受体对新烟碱类杀虫剂噻虫胺 (CLT)、吡虫啉 (IMI)、啶虫脒 (ACE) 和噻虫嗪 (TMX) 的敏感性较差，这与它们作为杀螨剂缺乏活性一致。有趣的是，在 1 μM PNU-120596 存在的情况下，电流幅度具有很强的潜力。CLT 作为激动剂比 IMI、TMX 和 ACE 更活跃。最后，我们证明了从蜱合成神经节纯化膜的微移植可以成为开发和筛选针对蜱烟碱乙酰胆碱受体亚型的化合物的宝贵工具。