Libersat F, Goldstein R S, Camhi J M
Department of Zoology, Hebrew University, Jerusalem, Israel.
Proc Natl Acad Sci U S A. 1987 Nov;84(22):8150-4. doi: 10.1073/pnas.84.22.8150.
Here we describe a nonsynaptic mechanism for filtering out potentially perturbing sensory feedback during locomotion. During flight, the cockroach moves its cerci, two abdominal sensory appendages, about their joint with the body and holds them in place. The cerci bear highly sensitive wind-receptive hairs, which would be strongly stimulated by flight wind. Such wind could cause habituation of the synaptic connections from these cercal receptors onto interneurons responsible for the running escape response to an approaching predator. We have found that the cercal displacement blocks one-third to one-half of the action potentials along the sensory nerve, possibly aiding in protection against such habituation. This block occurs if one experimentally displaces a cercus, and the block persists in the complete absence of any connections with the central nervous system. The block appears to be nonsynaptic and to result instead from mechanical pressure on the nerve near the joint. The results suggest that activity in peripheral nerves in other animals may also be affected by the position or movement of joints through which the nerves pass.
在此，我们描述一种用于在运动过程中滤除潜在干扰性感觉反馈的非突触机制。在飞行过程中，蟑螂会移动其尾须，即腹部的两个感觉附器，使其围绕与身体的关节活动并保持在相应位置。尾须上长有高度敏感的受风毛，飞行时产生的风会强烈刺激这些风毛。这样的风可能会导致从这些尾须感受器到负责对接近的捕食者做出逃跑反应的中间神经元的突触连接产生习惯化。我们发现，尾须的位移会阻断沿感觉神经三分之一到二分之一的动作电位，这可能有助于防止这种习惯化。如果通过实验移动尾须，就会出现这种阻断，并且在与中枢神经系统完全没有任何连接的情况下，这种阻断仍然持续存在。这种阻断似乎是非突触性的，而是由关节附近神经上的机械压力导致的。这些结果表明，其他动物外周神经的活动也可能受到神经所穿过关节的位置或运动的影响。
