Responses of infrared-sensitive tectal units of the pit viper Crotalus atrox to moving objects
Responses of infrared-sensitive tectal units of the pit viper Crotalus atrox to moving objects
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DOI：
10.1007/s00359-016-1076-1
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发表时间：
2016-02
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影响因子：
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通讯作者：
F. Kaldenbach;H. Bleckmann;Tobias Kohl
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文献类型：
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作者：
F. Kaldenbach;H. Bleckmann;Tobias Kohl
响尾蛇用它们的窝器官感知红外辐射。这使它们即使在黑暗中也能发现并攻击温血猎物。此外，红外线的感觉让响尾蛇找到地方进行体温调节。动画对象（例如，猎物）倾向于移动，从而引起移动的红外图像穿过纹孔膜。即使物体静止不动，响尾蛇头部的扫描运动也会导致红外图像穿过纹孔膜移动。 我们记录了响尾蛇（Crotalus atrox）顶盖红外敏感神经元的神经活动，同时用不同速度水平移动的红外源刺激蛇。只要物体速度较低（角速度约为5°/s），顶盖IR敏感神经元几乎不显示任何反应。随着物体速度的增加，神经元活动在~50°/s时达到最大值。物体速度进一步增加到~120°/s，导致神经元活动略有减少。我们的研究结果表明，移动刺激的蛇的红外检测能力的重要性：在快速移动的物体，静止或缓慢移动的物体将不会被检测到时，蛇是不动的，但可能会被检测到通过扫描头部运动。
Rattlesnakes perceive IR radiation with their pit organs. This enables them to detect and strike towards warm-blooded prey even in the dark. In addition, the IR sense allows rattlesnakes to find places for thermoregulation. Animate objects (e.g., prey) tend to move and thus cause moving IR images across the pit membrane. Even when an object is stationary, scanning head movements of rattlesnakes will result in moving IR images across the pit membrane. We recorded the neuronal activity of IR-sensitive tectal neurons of the rattlesnakeCrotalus atroxwhile stimulating the snakes with an IR source that moved horizontally at various velocities. As long as object velocity was low (angular velocity of ~5°/s) IR-sensitive tectal neurons hardly showed any responses. With increasing object velocity though, neuronal activity reached a maximum at ~50°/s. A further increase in object velocity up to ~120°/s resulted in a slight decrease of neuronal activity. Our results demonstrate the importance of moving stimuli for the snake’s IR detection abilities: in contrast to fast moving objects, stationary or slowly moving objects will not be detected when the snake is motionless, but might be detected by scanning head movements.