[Central modulation of a sensory system by a motor command. One intention with two results]

Neuronal mechanisms that underlie diverse sensory motor integration processes (SMI) are essential for the motor control and determine the general organization of the nervous system. Spinal cord, sensory relay nucleus of brainstem and thalamus as well as higher motor control structures are some of the levels, of increasing complexity, at which several processes of SMI occurs during the execution of a motor act. The mechanisms that underlie SMI strategies operating at higher hierarchical levels of motor control are poorly understood. Escape response in teleosts fish is an advantageous experimental model for the analysis of the neural basis of behavior and of the mechanisms and functional consequences of diverse strategies of ISM. We describe several levels of ISM that operate in the neural system that organize this response in most teleosts and we deal with a detailed description of a novel strategy that occurs in Gymnotus carapo, a South American weakly electric fish. In this species, the activation of the Mauthner cell, a command neuron for the initial phase of escape, produces a powerful modulation of the sensory system responsible for active electrorreception, its main sensory modality.

The neural basis of behavior, even those relatively simple, exhibit several strategies of complex SMI that determine its performance and whose cellular mechanisms begin to be unraveled.