There are several species of weakly electric fishes that produce small repetitive discharges from their electric organs, and assess objects in their environment by monitoring distortions of the electric field that they produce. Studies of the physiology and behavior of these electrosensory systems have revealed principles of neuronal coding and processing of information which also characterize systems such as vision and audition in other vertebrates. This work concentrates on groups of nerve cells, called nuclei, in a central region of the brain called the diencephalon, which lies just in front of the midbrain region. Studies have already shown that the diencephalic nuclei, unlike those in the midbrain, contain neurons dedicated to the generation of specific behaviors by the whole fish in using its electric organ discharge. This study will investigate the structure, function, and interconnections of these neurons from different nuclei using a variety of physiological and anatomical tracing techniques. Behaviorally relevant stimulus paradigms will be used to test the response properties of individual neurons along pathways involved in control of specific behavioral responses. This fruitful model system will generate results important to a range of sensory sciences, to behavior, and to computational neuroscience.
