Hybrid electrogenesis supports signal multiplexing in weakly electric fish

Abstract

Multiplexing diverse signals within a singular carrier facilitates interference-free information sharing among multiple users. This phenomenon is exemplified by electric fish, which emit self-generated electric fields conveying both exploratory and communicative signals. Here we show that an early component of the fish’s discharge resists curarization and originates precisely where silver impregnation identifies expansions of electromotor axons, thereby indicating a neuro-electrogenic nature. Although this component temporally overlaps with a myogenic component of opposing polarity, modeling reveals that such opposition potentiates a spatial filtering process which fine-tunes the balance between components causing distinct stimuli on the sensory mosaics of the emitter and its neighbors. Since electroreceptors are exquisite sensitive to the time course of sensed stimulus, this mechanism contributes to the discrimination between exploratory and communication signals.