Rother Diego, Migliaro Adriana, Canetti Rafael, Gómez Leonel, Caputi Angel, Budelli Ruben
Sección Biomatemática, Facultad de Ciencias, Iguá 4225, Montevideo, Uruguay.
Biosystems. 2003 Sep;71(1-2):169-77. doi: 10.1016/s0303-2647(03)00124-2.
Electroreceptive fish detect nearby objects by processing the information contained in the pattern of electric currents through their skin. In weakly electric fish, these currents arise from a self-generated field (the electric organ discharge), depending on the electrical properties of the surrounding medium. The electric image can be defined as the pattern of transepidermal voltage distributed over the receptive surface. To understand electrolocation it is necessary to know how electric image of objects are generated. In pulse mormyrids, the electric organ is localized at the tail, far from the receptors and fires a short biphasic pulse. Consequently, if all the elements in the environment are resistive, the stimulus at every point on the skin has the same waveform. Then, any measure of the amplitude (for example, the peak to peak amplitude) could be the unique parameter of the stimulus at any point of the skin. We have developed a model to calculate the image, corroborating that images are spread over the whole sensory surface and have an opposite center-surround, "Mexican-hat" shape. As a consequence, the images of different objects superimpose. We show theoretically and by simulation that the image of a pair of objects is not the simple addition of the individual images of these objects.
电感受性鱼类通过处理流经其皮肤的电流模式中所包含的信息来探测附近的物体。在弱电鱼中，这些电流源自自身产生的电场（电器官放电），这取决于周围介质的电学特性。电图像可定义为分布在感受表面上的经表皮电压模式。为了理解电定位，有必要了解物体的电图像是如何产生的。在脉冲长颌鱼中，电器官位于尾部，离感受器较远，且会发出一个短的双相脉冲。因此，如果环境中的所有元素都是电阻性的，那么皮肤上每个点的刺激都具有相同的波形。那么，任何幅度测量（例如峰峰值幅度）都可能是皮肤任何一点上刺激的唯一参数。我们已经开发了一个模型来计算图像，证实图像分布在整个感觉表面上，并且具有相反的中心 - 外周“墨西哥帽”形状。因此，不同物体的图像会叠加。我们从理论上和通过模拟表明，一对物体的图像不是这些物体各自图像的简单相加。
