Neural Representation of Object’s Shape at the Electroreceptor Afferents on Electrolocation

Abstract

A weakly electric fish can recognize object’s shape in the complete darkness. The ability to recognize object’s shape is provided by the electrosensory system of the fish. The fish generates an electric field using its electric organs (EOD: electric organ discharge). An object around the fish modulates the self-generated EOD. Electroreceptor afferents on the fish’s body surface convert the EOD amplitude modulation into firings. The fish can extract information about object’s shape from the EOD amplitude modulation using its electrosensory system. In the present study, we calculated the EOD amplitude modulation evoked by objects that were various shapes and firing patterns of the electroreceptor afferents evoked by the EOD amplitude modulation using computer simulation. We found that the EOD amplitude modulation can be represented by firing patterns of the electroreceptor afferents. Furthermore, we demonstrated that the feature of object’s shape appears in the variation of the peak of firing rate with the rotation of the object.