Temporal and directional processing by an identified interneuron, ON1, compared in cricket species that sing with different tempos.

We compare the temporal and directional processing properties of an identified auditory interneuron, ON1, between species with calling songs containing relatively low and high pulse rates (Teleogryllus oceanicus and Gryllus texensis, respectively). Using information theory, we find that the ON1 of G. texensis encodes higher amplitude-modulation frequencies than that of T. oceanicus. Bilateral differences in ON1 responses are also more pronounced in G. texensis, particularly for rapid, G. texensis-like stimuli. We show that brief silent intervals in a pulse train, such as those that occur in the natural calling song of G. texensis, enhance the representation of the stimulus pulse pattern as well as bilateral differences in activity. Our results suggest that the characteristics of an identified neuron vary, across cricket species, in accordance with the temporal structures of their communication signals.