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

Kakenhi项目让我们能够制造出一种设备，通过高清x射线电影系统来研究老鼠的下颌运动。射线照相技术的使用使我们能够以详细和微创的方式研究小鼠的详细颌骨运动。在这项研究中，我们分析了重力减速下动物的姿势变化。采用抛物线飞行对小鼠进行部分重力减速。因此，重力减速产生了头部、下颌、脊柱和后肢的协调和广泛的伸展。相对于平均1g姿势，部分重力状态下的关节角度扩大了30%或更多。重力减速时，观察到反射性开颚。姿势反应的大小与重力减速呈正相关。这些结果表明，对部分重力的适应性可能不仅取决于部分重力水平，还取决于任何给定部分重力水平的重力变化率。

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.