Influence of high steady magnetic fields on the electrical activity of the electric fish Apteronotus.

We have investigated the influence of strong dc. magnetic fields--ranging up to 10 Tesla--on the weak sinusoidal electric signals which the electro-fish Apteronotus is known to emit. We made the following observations: 1. The amplitude of the sinusoidal electric signals rises with the application of the dc. magnetic fields, increasing by about 8% in a field of 10 Tesla. 2. The frequency of the signals of about 570 Hz was not at all affected by the field but remained constant in fields up to 10 Tesla. Since the electric signals of Apteronotus are of neural origin our experiments indicate an influence of strong dc. magnetic fields on the nervous system of this electric fish.