The major research project is to study physiological mechanisms of sustained high frequency spiking and synaptic transmission which are found in the nerve-electroplaque preparation of several electric fish. Preparations are selected from low to high frequency discharging electric fish: Electrophorus (less than 2 Hz, for brief period), Gymnotus (50 Hz sustained) and Eigenmannia (250-500 Hz, sustained), in order to correlate natural discharge frequencies with excitable membrane properties. The low frequency synaptic transmission operating in other animals is also studied for comparison.