Ultra-high speed x-ray movie recording of mandibular movements

这个Kakeni项目使我们能够建造一种设备，通过高清晰度X射线电影系统来研究老鼠的颌骨运动。电影放射摄影技术的使用使我们能够以详细和微创的方式研究小鼠详细的下颌运动。在这项研究中，我们分析了暴露在重力减速下的动物的姿势变化。通过抛物线飞行将小鼠置于部分重力减速状态。结果，重力减速产生了头部、颌骨、脊柱和后肢的协调和普遍的伸展。与平均1g姿势相比，偏重状态下的关节角度增加了约30%或更多。在重力减速过程中观察到反射性张口。姿势反应的大小与重力减速呈正相关。这些结果表明，对偏重的适应性可能不仅取决于偏重水平，而且还取决于重力变化到任何给定的偏重水平的速度。

This Kakenhi project allowed us to build a device for the study of jaw movements in the mouse through a high-definition x-ray movie system. The use of cineradiographic technology enabled us to study detailed jaw movements in the mouse in a detailed and minimally invasive fashion. In this study, we analyzed postural changes in animals exposed to gravity deceleration. Mice were exposed to partial-gravity deceleration by parabolic flights. As a result, gravity deceleration produced coordinated and generalized extension of head, jaw, spine, and hindlimbs. Joint angles in partial gravity widened about 30% or more in relation to the average 1 g posture. Reflex jaw-opening was observed during gravity deceleration. The magnitude of postural responses was associated positively with gravity deceleration. These results suggest that adaptability to partial gravity may be not only dependent on the partial-gravity level, but also on the rate of gravity change into any given partial-gravity level.