マウスの尻尾を用いたバランス機能の解明

介绍：对小鼠的研究表明，尾巴对平衡很重要。然而，这一假设从来没有得到解决的高分辨率运动捕捉，实现这一运动程序的神经元系统是目前未知的。在本课题中，我研究了在平衡运动反应中起重要作用的前庭系统对尾巴的运动控制的功能作用。在上一个财政年度，我解决了两个主要问题：（1）在脊任务中，小鼠是否以及如何使用尾巴来保持平衡;（2）脊髓中的尾运动神经元是否接受前庭核的投射。脊实验（1）：我们发现，小鼠采用两种策略与他们的尾巴，以适应较小的宽度：尾巴摆动幅度较大，和尾巴的位置更接近滚动平面的小鼠。我们推测，最后一种策略可以使小鼠增加尾巴在滚转平面上的有效长度。前庭投射到尾部MN的标记（2）：这部分项目的目标是评估脊髓中的尾部运动神经元是否接受来自前庭核的投射。在这个框架内，第一个实现的目标是在脊髓尾运动神经元（MN）池的识别。为了确定MN池中神经元的大致数量，我肌内注射了霍乱毒素亚单位（CTb）。

Introduction: Studies in mice have suggested that the tail is important for balance. However this hypothesis has never been addressed with high resolution motion capture, and the neuronal system that implement this motor program is currently unknown. In the project described here, I study the functional role of the vestibular system, which plays an important role in balancing motor responses, for the motor control of the tail.In the last fiscal year, I addressed the two main questions:(1) whether and how mice use their tail to maintain balance in the ridge task(2) whether tail motoneurons in the spinal cord receive projections from the vestibular nuclei.Ridge experiment (1): We revealed that mice employ two strategies with their tails to adapt to the smaller widths: the tail swing amplitude is bigger, and the tail is positioned closer to the roll plane of the mouse. We speculate that this last strategy allows the mouse to increase the effective length of the tail in the roll plane.Labeling of vestibular projections onto tail MNs (2): The goal of this part of the project is to assess whether tail motoneurons in the spinal cord receive projections from the vestibular nuclei. Within this framework the first achieved objective was the identification of the tail motoneurons (MN) pool in the spinal cord. In order to identify the approximate number of neurons that the MN pool consists of, I injected intramuscularly cholera toxin subunit (CTb).