The analysis of the action-perception cycle in Gymnotus omarorum has proven that this native species is an excellent model system to study the dynamics of this loop and the implementation mechanisms of its different stages. This analysis provided insight into cell and synaptic function, plasticity, circuitry ensemble, and neural codes. This research has also contributed to the development of Neuroscience that led to the foundation of the Sociedad Uruguaya de Neurociencias which anniversary this issue celebrates. This article first considers the features that these fish offer to the conceptual analysis of reafferent systems. Second, it focuses on some of the stages involved in the sensory effector cycle. This includes the analysis of: a) how the electromotor system contributes to the understanding of central pattern generators of rhythms and action patterns
b) how electric images are formed, peripherally encoded, and contribute to the understanding of how imaging molds perception
c) how sensory detection and behavioral responses to novel events may be used for describing the dynamics of the cycle
d) how the pulsed imaging strategy illustrates the importance of using a code of packeted well timed spikes for fast detection of sensory features
and e) how the interactions between electro- and skeletomotor control using the Mauthner initiated escape response serve as a useful neuroethological case study. We conclude by considering some still open questions and research perspectives that, together with the exceptional advantages offered by electric fish, provide promising advances in the general understanding of the neural basis of the sensory-motor loop.