Role of the ribbon synapse in high-frequency neural phase locking

带状突触在高频神经锁相中的作用

• 批准号: 279586716
• 负责人: Professorin Dr. Christine Köppl
• 金额: --
• 依托单位: Department für Neurowissenschaften
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/279586716?language=en
• 关键词: Role; ribbon; synapse; frequency; neural

In humans and animals with good low-frequency hearing, phase locking by the afferent fibres of the auditory nerve is known to be a salient temporal code for the central auditory system. The temporal dispersion of spiking in phase-locking auditory-nerve fibres can be as low as 30 µs. This represents ultrafast and temporally precise information processing at its extreme. However, the underlying cellular mechanisms are not well understood. This project aims to explore the specific role of the hair-cell ribbon synapse in this process. The chicken is chosen as the model organism because it combines 1) robust auditory-nerve phase-locking into the kHz-range with 2) good accessibility of early embryonic stages in-ovo for established techniques of virus-mediated gene misexpression. We have a chicken model available with an aberrant phenotype in one ear that specifically changes the hair cells and their innervation, such that an increased number of synaptic ribbons connects to each afferent fibre. This will allow for testing the recently suggested mechanism that tightly synchronised multi-vesicular transmitter release is crucial for the normal temporal precision observed in neural phase locking. We predict that, especially near the upper frequency limit of phase locking, an increased number of ribbon sites will degrade the synchronisation and thus degrade the temporal precision of spiking. This will be quantified with several metrics in vivo. Our bird work will complement ongoing work on mouse hair cells by extending the concepts and available toolbox for unravelling the mechanisms for ultrafast processing at this very specialised first synapse in the auditory pathway.

在具有良好低频听力的人类和动物中，听觉神经的传入纤维的相位锁定已知是中枢听觉系统的显著时间代码。锁相神经纤维中尖峰脉冲的时间离散度可以低至30 µs。这代表了极端的超快和时间精确的信息处理。然而，潜在的细胞机制还没有很好地理解。本项目旨在探索毛细胞带状突触在这一过程中的具体作用。选择鸡作为模型生物体，因为它结合了1）在kHz范围内稳健的神经锁相和2）对于病毒介导的基因错误表达的已建立技术而言，早期胚胎阶段在卵内的良好可及性。我们有一个鸡模型，在一只耳朵中有一个异常的表型，它特异性地改变了毛细胞及其神经支配，使得连接到每个传入纤维的突触带数量增加。这将允许测试最近提出的机制，即紧密同步的多囊泡递质释放对于在神经相位锁定中观察到的正常时间精度至关重要。我们预测，特别是接近频率上限的相位锁定，带状网站的数量增加会降低同步，从而降低尖峰的时间精度。这将在体内用几个指标进行量化。我们的鸟类工作将通过扩展概念和可用工具箱来补充正在进行的小鼠毛细胞工作，以解开听觉通路中这个非常专业的第一个突触的超快处理机制。