Functioning of catfish electroreceptors: Influence of calcium and sodium concentration on the skin potential

Abstract

1. 1. The skin potential of catfish was measured in order to test the hypothesis that it controls electroreceptor sensitivity.

2. 2. The skin potential depends on the “milieu extérieur” in the same way as reported lor goldfish (Fig. 2).

3. 3. The variation of the skin potential is very large compared with the normal stimulus range of electroreceptors.

4. 4. Calcium strongly influences the skin potential, but the latter “adapts” to calcium concentrations of 0.3-3.0 mM (Fig. 3).

5. 5. Ion-dependence of the skin impedance cannot seriously alter receptor sensitivity.