Kalmijn A D
Scripps Institution of Oceanography, Physical Oceanography Research Division, University of California--San Diego, La Jolla 92093-0220, USA.
Philos Trans R Soc Lond B Biol Sci. 2000 Sep 29;355(1401):1135-41. doi: 10.1098/rstb.2000.0654.
The acoustic near field of quietly moving underwater objects and the bio-electric field of aquatic animals exhibit great similarity, as both are predominantly governed by Laplace's equation. The acoustic and electrical sensory modalities thus may, in directing fishes to their prey, employ analogous processing algorithms, suggesting a common evolutionary design, founded on the salient physical features shared by the respective stimulus fields. Sharks and rays are capable of orientating to the earth's magnetic field and, hence, have a magnetic sense. The electromagnetic theory of orientation offers strong arguments for the animals using the electric fields induced by ocean currents and by their own motions in the earth's magnetic field. In the animal's frame of reference, in which the sense organs are at rest, the classical concept of motional electricity must be interpreted in relativistic terms. In the ampullae of Lorenzini, weak electric fields cause the ciliated apical receptor-cell membranes to produce graded, negative receptor currents opposite in direction to the fields applied. The observed currents form part of a positive-feedback mechanism, supporting the generation of receptor potentials much larger than the input signal. Acting across the basal cell membranes, the receptor potentials control the process of synaptic transmission.
安静移动的水下物体的声学近场与水生动物的生物电场表现出极大的相似性，因为两者主要都由拉普拉斯方程支配。因此，在引导鱼类寻找猎物时，声学和电感觉模态可能采用类似的处理算法，这表明基于各自刺激场共有的显著物理特征，存在一种共同的进化设计。鲨鱼和鳐鱼能够定向于地球磁场，因此具有磁感觉。定向的电磁理论为动物利用洋流以及它们自身在地球磁场中的运动所感应的电场提供了有力论据。在动物的参考系中，感觉器官处于静止状态，运动电的经典概念必须用相对论的术语来解释。在罗伦氏壶腹中，弱电场会使有纤毛的顶端受体细胞膜产生分级的负受体电流，其方向与所施加的电场相反。观察到的电流是正反馈机制的一部分，支持产生比输入信号大得多的受体电位。受体电位作用于基底细胞膜，控制突触传递过程。
