衰老小鼠前庭系统的行为评估
Summary
电机控制和平衡性能是众所周知的恶化与年龄。本文介绍了一些非侵入性的标准行为测试与另外一个简单的旋转刺激衰老小鼠模型，以挑战在平衡性能前庭系统和显示的变化。
Abstract
在平衡性能与年龄有关的下降与不断恶化的肌肉力量，运动协调和前庭功能相关联。虽然一些研究显示变化的平衡表现型与年龄在啮齿类动物中，只有极少数孤立前庭贡献下正常情况下或在衰老期间的平衡。我们用两个标准行为测试在规定的年龄分以上的寿命来表征小鼠的平衡性能：旋转试验和斜平衡木测试。重要的是，一个定制的旋转体也被用来刺激小鼠的前庭系统（而不诱发运动病明显的迹象）。这两个测试已经被用来表明改变前庭介导的平衡性能是目前在鼠的寿命。初步的结果表明，无论是旋转试验和改性平衡木测试可用于老化作为替代更diffic期间识别变化的平衡性能ULT和侵入性技术，如前庭眼（VOR）的测量。
Introduction
我们的平衡感，也许是连最基本的运动活动，包括散步和车削中最容易被忽视但非常重要的组成部分之一。平衡是由很多因素，包括肌肉力量，运动协调和前庭功能的影响，并且它仅在前庭神经病变的存在或不正常的老化过程中，一个全功能的平衡系统的重要性理解。扰动前庭系统往往以眩晕或头晕及不平衡导致摔倒和受伤以后1的风险增加的经验有关。这是在老年人群跌倒的地方是2伤的主要原因之一尤为关键。
前庭功能检查通常是基于前庭反射，尤其是前庭眼（VOR）或前庭collic反射（录像机）。在VOR和录像机是必不可少的图像上的稳定头部和身体的动作分别在视网膜和头部位置。一般情况下，VOR测量需要的搜索线圈微创植入测量眼球运动或眼球运动3的视频跟踪。这是在小鼠由于老鼠的眼睛和检测瞳孔的视频分析3难度小自然充满挑战。作为替代方案，录像机已被用来测量头的稳定响应于身体的动作小鼠而不需要侵入性手术4。尽管如此，一些研究特别侧重于前庭系统是如何执行作为一个整体，更重要的是它的老化过程中是如何变化的。
评估的综合平衡性能简单，无创，我们修改两个常用的行为测试。该旋转杆，斜平衡木测试评估啮齿动物和在以前的研究中电机性能的不同方面已经用于测试电池获得一个完整的简介电机能力。这种能力可能受疾病或遗传修饰，并且还以与正常发育和老化5-7相关联的处理敏感。使用旋转杆早期的工作表明，在小鼠运动协调3个月8岁后下降。此外，老鼠显示出明显的平衡赤字的平衡木测试9年龄的增加。
本文描述了为了挑战前庭系统和年轻人和年纪较大的老鼠表征上的平衡性能的后续影响使用与前庭刺激相结合的旋转杆和平衡木测试。虽然描述的简单，无创的方法并非设计为外周前庭功能独立的措施，他们也提供了一个有用而简单的行为措施，在前庭处理的多个阶段的小鼠正常老化过程中，比较细胞和亚细胞的变化。
Protocol
Representative Results
Discussion
该议定书中的关键步骤
以前的工作已经表明，它很容易训练过度小鼠同时在旋转杆和平衡梁装置和作为结果，获得准确的测量结果可以是具有挑战性15。例如，过度训练对转棒可导致在这两个驯化和试用期的小鼠故意跳下销钉，而过度训练平衡木上可能会导致更频繁的停车（探索行为），并在相反方向行驶（ 即对启动线）15。最终，过度训练可导致电机实…
Disclosures
The authors have nothing to disclose.
Acknowledgements
The authors would like to acknowledge The Garnett Passe and Rodney Williams Memorial Foundation and the Bosch Institute Animal Behavioural Facility.
Materials
| Rotarod | IITC Life Science Inc. | #755 | "Rat dowels" = 70 mm diameter. Do not allow ethanol contact perspex. |
| iPhone | Apple | Can use any type of camera (e.g. Logitech webcam described above). Velcro fixed to the back surface for attachment to the the 3D articulated arm. | |
| 3D articulated arm | Fisso/Baitella | Classic 3300-28 | Any type of stable vertical stand would be adequate. Velcro is fixed to the apical end of the arm for iPhone attachment. |
| Wooden walking beam: 1m long strip of smooth wood with a circular cross-section of 14 mm diameter | A range of diameters and cross section shapes can be used to suit experimental parameters | ||
| Wooden goal box (130 x 140 x 220 mm) made from 11 mm thick boards | |||
| Support stand made of 41 x 41 mm beams: 2 vertical beams 525 and 590 mm from ground at the start and goal ends respectively; 803 mm horizontal beam that runs along the ground directly under the walking beam; two 20 mm long beams act as "feet", joining the horizontal and vertical beams at each end; a 21 x 21 x 36 mm block hewn at the apical end of the "starting" vertical beam; a 13 x 13 mm aperture cut out of the centre of this block, forming a tunnel which runs perpendicular to the walking beam. | Brace all joins with small steel brackets. | ||
| Adjustible metal ring (13 mm wide) | Pass this through the aperture in the block, pass the starting end of the balance beam through this ring and tighten until the beam is firmly in place. | ||
| Black paint (water based) | Handycan | Acrylic Matt Black | 2-3 coats for all wooden surfaces of the balance beam apparatus |
| Clear finish | Wattle Estapol | Polyurethane Matt | Single coat for all beams. Double coat for all other surfaces of the balance beam apparatus |
| Foam, packaging material | To cushion any falls from the balance beam | ||
| Electrical tape | Fix webcam to roof. | ||
| 70% Ethanol, paper towels | Clean beam and goal box between each animal. | ||
| Gauze pads/paper towels | To line the floor of the goal box | ||
| Mouse house (from home cage) |
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