Drosophila use acoustic communication signals during courtship, but little is known about the representation of acoustic stimuli in central auditory pathways. The goal of this study is to understand how central auditory neurons transform acoustic signals downstream of primary auditory neurons. We have identified central auditory neurons whose processes arborize in the region of the brain that receives input from primary auditory neurons. Using in vivo whole-cell patch clamp recordings and a combination of acoustic and piezoelectric stimuli, we are investigating the connectivity and receptive field properties of these neurons. Our preliminary findings indicate that these neurons faithfully encode low-frequency amplitude modulations. Pilot pharmacological experiments suggest that GABAergic inhibition plays a key role in shaping the responses of these neurons. These findings demonstrate the feasibility of Drosophila as a useful model for understanding central auditory processing. Future experiments will exploit the unique genetic toolbox available for Drosophila in order to gain a better understanding of how these neurons fit into an auditory circuit as well as the cellular, synaptic, and circuit mechanisms underlying their computations.
Understanding auditory processing in the fly will provide important insights into the function of auditory systems in more complex animals, including, ultimately, the human auditory system. This, in turn, is relevant to the treatment of hearing disorders, including the design of hearing aids and prosthetic hearing devices. For example, the study of a fly auditory system has already led to the development of a biologically-inspired directional microphone for hearing aids.