Development of insect mechanosensory neurons

检测机械信号的神经细胞对触觉、听觉、平衡和疼痛等多种感官都很重要。他们还监测身体的位置。神经末梢的机械敏感离子通道响应感官刺激而打开，离子通过这些通道的通量引起膜电位的变化。这导致神经冲动沿感觉轴突传播，神经递质从轴突末端释放并将感觉信息传递到中枢神经系统。神经冲动的传播可以通过其他神经元的突触输入来调节。我们的研究计划旨在了解机械感觉神经元的发育和机械感觉的详细过程。我们使用的实验动物是一种大蛾子，Manduca sexta，它经历了从卵到毛虫再到蛹的完整蜕变，最后成为一只成年蛾子。成虫的神经发育发生在两周的蛹期，在此期间神经系统相对容易进行实验研究，使得在每个发育阶段进行实验成为可能。我们研究的机械感觉神经元位于长长的阑尾，即触角，可以很容易地分离出来并用于实验，这在哺乳动物身上是不可能的。我们的研究计划旨在了解发生在感觉神经元和其他细胞之间的特定分子相互作用，以引导发育中的神经轴突到达大脑中的最终目的地。我们还想了解机械敏感成分的分子结构以及将它们放置到这些神经元的感觉末端的机制。我们从这项研究中获得的知识将为实验中可获得的昆虫机械感觉系统的细胞和发育过程提供见解。然而，在脊椎动物机械感觉器官中，许多结构和过程是相似的，这在实验研究中明显较少。

Nerve cells that detect mechanical signals are important for a wide range of senses, such as touch, hearing, balance and pain. They also monitor the position of the body. Mechanosensitive ion channels in the specialized nerve endings open in response to sensory stimuli and ion flux thorough these channels causes a change in membrane potential. This leads to propagation of nerve impulses along the sensory axon, release of neurotransmitter from the axon terminal and transfer of the sensory information to the cental nervous system. Propagation of nerve impulses can be modulated by synaptic inputs from other neurons. Our research program aims to learn how the mechanosensory neurons develop and the detailed processes involved in mechanosensation. The experimental animal we use is a large moth, Manduca sexta, that undergoes a full metamorphosis from an egg to a caterpillar to a pupa, finally emerging as an adult moth. The adult neural development occurs during the two-week pupal period, during which the nervous system is relatively easily accessible for experimental research, making it possible to perform experiments at each developmental stage. The mechanosensory neurons that we study are located in long appendices, the antennae, and can be easily isolated and used in experiments that would not be possible in mammals. Our research program aims to learn the specific molecular interactions that occur between the sensory neurons and other cells to guide the developing nerve axons to their final destinations in the brain. We also want to learn the molecular structures of the mechanosensitive components and the mechanisms involved in placing them to the sensory endings of these neurons. The knowledge that we gain from this research will offer insight in the cellular and developmental processes in an experimentally accessible insect mechanosensory system. However, many of the structures and processes are similar in vertebrate mechanosensory organs that are significantly less accessible for experimental research.