Neurogenetics Group, College of Life Sciences, University of Leicester, University Road, Leicester, Leicestershire LE 7RH, UK.
Department of Cellular Neurobiology, University of Göttingen, Schwann-Schleiden Research Centre, Julia-Lermontowa-Weg 3, 37077 Göttingen, Germany.
J Exp Biol. 2024 Sep 1;227(17). doi: 10.1242/jeb.246197. Epub 2024 Sep 9.
Mechanosensitive ensembles of neurons in insects, known as chordotonal organs (COs), function in proprioception, the detection of sound and substrate vibrations. Here, we characterized the mechanical sensitivity of the lateral pentascolopidial CO (lch5) of Drosophila melanogaster larvae to establish its postulated role in proprioception. We developed a physiologically realistic method to replicate proprioceptive input to lch5 by pulling the apodeme (tendon) to which the tips of the neurons attach. We found that lch5 sensory neurons respond transiently with a short latency to the velocity component of stretch displacements and the release of stretch (relaxation). In the mechanosensory mutant inactive, lch5 has a decreased response to mechanical stimuli and a lower overall spontaneous spike rate. Finally, we simulated the input that lch5 receives during crawling and observed spike rate changes of peristaltic body contraction. We provide a characterization of proprioceptive feedback in D. melanogaster larvae and firmly establish the proprioceptive function of lch5 in larval locomotion.
昆虫中的机械敏感神经元集合，称为听弦器官（COs），在本体感觉、声音和基质振动的检测中发挥作用。在这里，我们对黑腹果蝇幼虫的侧向五感器 CO（lch5）的机械敏感性进行了表征，以确定其在本体感觉中的假定作用。我们开发了一种生理上逼真的方法，通过拉动神经元附着的尖端的附肢（肌腱）来复制对 lch5 的本体感觉输入。我们发现 lch5 感觉神经元对拉伸位移的速度分量和拉伸释放（松弛）的反应具有短暂的潜伏期。在机械感觉突变体 inactive 中，lch5 对机械刺激的反应减弱，整体自发尖峰率降低。最后，我们模拟了 lch5 在爬行过程中接收到的输入，并观察到蠕动体收缩的尖峰率变化。我们对黑腹果蝇幼虫的本体感觉反馈进行了表征，并确定了 lch5 在幼虫运动中的本体感觉功能。
