A key question in neuroscience is how sensory information is processed to control adaptive behavioral responses. An excellent system in which to study this issue is found in fish called weakly electric fish. These fish have an electric organ like that in the electric eel, but much weaker, and produce periodic discharges of particular waveforms. These fish also have electrosensory systems that detect the electric field produced by the fish itself or by other nearby electric fish. The electrosensory system is used for orientation and the pattern of signals is used for communication. The brain of these animals is now known to process the signals using certain kinds of spatial maps, comparable to those in the visual system, and using certain kinds of temporal analysis, comparable to processes in the auditory system. This project has its focus on a particular group of nerve cells, or nuclei, in the brain, located at an interface between the spatial representation of the midbrain, and the nuclei that produce the electric signalling behavior such as the prepacemaker nucleus, which modulate the discharge pattern of the electric organ. Anatomical and physiological techniques are used to label physiologically identified nerve cells to trace their functional connections in this circuit. Behaviorally relevant stimulus paradigms will be used to test the response properties of individual neurons along pathways involved in control of specific behavioral responses. Clarification of this circuitry for integrating complex sensory input into a discrete behavioral output in this model system will provide major advances for neuroscience, with importance to sensory systems, motor systems, integration, and behavior.
