Comparative Investigations of neuronal integration processes along the auditory pathway in simple systems

简单系统中听觉通路神经元整合过程的比较研究

• 批准号: 380914489
• 负责人: Professorin Dr. Manuela Nowotny
• 金额: --
• 依托单位: Institut für Zoologie und Evolutionsforschung
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/380914489?language=en
• 关键词: Comparative; Investigations; neuronal; integration; processes

Our world is full of physical stimuli that can be detected by sensory organs and evaluated by the brain. For reproduction or survival, the detection of sound waves is essential for many animals. Neurons along the auditory pathway are informed about surrounding sounds by synaptic inputs through afferent fibres of the ear. In simple hearing systems with only low synapse levels along the auditory pathway to the brain, such as in bushcrickets, the input to prothoracic ganglion is the first important signal integration centre. The neuronal response at this level is based on the spiking of primary sensory neurons that encode spectral as well as temporal information of the sound. While frequency discrimination in the ear, which is accomplished by tonotopical travelling waves, is well understood in bushcrickets, the dynamics of the temporal encoding is still under investigation and one focus of the current proposal. In this comparative study we will investigate the neuronal integration in two different bushcricket species. Both species show sex-specific differences in mating behavior, like phonotaxis and their ears feature significantly different morphologies. In one species, Ancylecha fenestrata, the hearing organ is extensively expanded and provides an overrepresentation of behaviorally important auditory input, an auditory fovea. In total about 110 axons project to the prothoracic ganglion. The other here analyzed species, Mecopoda elongata, has only about 45 axons sending projections to the prothoracic ganglion without any overrepresentation. Our comparative study will investigate the neuronal integration process in both species and aims to gain knowledge on the advantage to build up an auditory fovea. In this project we use multielectrode and intracellular recordings in the prothoracic ganglion to investigate the neuronal integration by local field potentials in a small network, which is determined by the sound-induced signals from the bushcrickets ear, which in turn are investigated by Laser Doppler Vibrometry, intracellular recordings and neuroanatomical studies.

我们的世界充满了感觉器官可以检测到的物理刺激，大脑可以对其进行评估。为了繁殖或生存，声波的探测对许多动物来说是必不可少的。通过耳朵传入纤维的突触输入，听觉通路上的神经元被告知周围的声音。在简单的听力系统中，沿着通往大脑的听觉通路只有低水平的突触，例如在丛林蟋蟀中，到前胸神经节的输入是第一个重要的信号整合中心。这一水平的神经元反应是基于初级感觉神经元的尖峰，初级感觉神经元编码声音的光谱和时间信息。虽然在丛林蟋蟀中，通过音调行波完成的耳朵中的频率辨别是众所周知的，但时间编码的动力学仍在研究中，也是当前提议的重点之一。在这项比较研究中，我们将研究两个不同的布氏蟋蟀物种的神经元整合。这两个物种在交配行为上表现出性别差异，比如趋音性，它们的耳朵特征也有显著的不同。在一种名为Ancylecha fenestrata的物种中，听力器官广泛扩大，并提供了行为上重要的听觉输入的过度表现，即听觉中心凹。总共约有110个轴突投射到前胸神经节。这里分析的另一个物种，长足类动物，只有大约45个轴突向前胸神经节发送投射，没有任何过多的表现。我们的比较研究将调查这两个物种的神经元整合过程，目的是了解建立听觉中心凹的优势。在这个项目中，我们使用多电极和前胸神经节的细胞内记录来研究局部场电位在一个小网络中的神经元整合，这是由来自布氏蟋蟀耳朵的声音诱导信号决定的，然后用激光多普勒测振仪、细胞内记录和神经解剖学研究来研究。