Miyachi Y
Department of Physiology, Toho University School of Medicine, Ohmori-nishi 5-21-16 Ohta-ku, Tokyo 143, Japan.
Behav Processes. 1996 Jun;36(3):297-301. doi: 10.1016/0376-6357(95)00035-6.
X-rays are commonly said to be one of many stimulus agents which are not perceivable by the sensory organs of mammals. However, I observed an interesting phenomenon where a mouse lifted its head and looked up (head-up behavior) while keeping its body flat on the floor when a mouse was given low-doses whole-body X-irradiation emitted from above. An attempt was made to examine whether mice could discern the direction of an X-ray source. I observed EEG responses and the head-up behavior when the mice were exposed to 4 cGy X-rays from more than one angle. The results showed that the mice awoke immediately and displayed the head-up behavior when those showing non-REM sleep were given 4 cGy X-rays emitted from above, below or from the side of the mouse. Mice showing REM sleep, however, showed no such behavior. Furthermore, the head-up behavior was not observed at all, even after 4 cGy X-irradiation, when the mouse was deprived of its olfactory sense by ZnSO4 solution. These results show that mice could detect low-doses of X-rays, without knowing the direction of the source, and peripheral olfactory cells were possibly involved in this detection.
通常认为，X射线是哺乳动物感觉器官无法感知的多种刺激源之一。然而，我观察到一个有趣的现象：当给一只小鼠从上方进行低剂量全身X射线照射时，它会抬起头向上看（抬头行为），同时身体平贴在地面上。有人试图研究小鼠是否能够辨别X射线源的方向。当小鼠从多个角度暴露于4 cGy的X射线下时，我观察了它们的脑电图反应和抬头行为。结果表明，当处于非快速眼动睡眠状态的小鼠从上方、下方或侧面接受4 cGy的X射线照射时，它们会立即醒来并表现出抬头行为。然而，处于快速眼动睡眠状态的小鼠则没有这种行为。此外，当用硫酸锌溶液剥夺小鼠的嗅觉后，即使在接受4 cGy的X射线照射后，也完全没有观察到抬头行为。这些结果表明，小鼠能够检测到低剂量的X射线，而无需知道射线源的方向，并且外周嗅觉细胞可能参与了这种检测。
