Our lab focuses on the study of the molecular structures involved in synaptic transmission between efferent neurons that descend from the brain and the organ of Corti, the sensory epithelium of the inner ear. We and our collaborators discovered the molecular structure of the receptors for the neurotransmitter acetylcholine expressed by cochlear hair cells. They proved, contrary to expectation, that the hair cell cholinergic receptor is related to the ‘nicotinic’, ionotropic receptors of nerve and muscle and not to G-protein-coupled receptors as originally thought. These discoveries not only greatly expanded our understanding of this important family of neuronal proteins, but are also opening new avenues to therapeutics of the inner ear. Finally, my lab is extended its scientific impact by the creation of genetically-modified mice with altered feedback control of hearing. Through the analysis of these mouse models, we are helping towards understanding some of the functions of this efferent feedback e.g., the correct establishment of synaptic contacts within the cochlea and the protection from trauma produced by the exposure to loud sounds.