"The ear listens to the brain: the efferent olivocochlear system"

ELGOYHEN AB

Conferencia; Collège de France, Conferencias Magistrales; 2018

Collège de France

In bringing information about the world to an individual, sensory systems perform a series of commonfunctions. Each system responds with some specificity to a stimulus and each one employs somespecialized receptor cells at the periphery to translate specific stimuli into electrical signals that allneurons can use. That initial electrical event begins the process by which the central nervous systemconstructs an orderly representation of for example, sounds, odors, tastes and objects. Thus, basicsound detection begins when sound waves strike the eardrum, which transmits that physical stimulus tothe organ of Corti within the cochlea, the sensory epithelium of the mammalian inner ear. Here theprimary receptor cells known as inner hair cells transform the information into electrical signals that aresent to the central nervous system by the auditory nerve. However, unlike vision, touch and thechemical senses, sound processing is modulated by efferent signals that travel in reverse, from the brainback to the inner ear. One fundamental question in auditory neuroscience is what role(s) this feedbackplays in our ability to hear. The presentation will overview our work over the years which hascontributed to elucidate the molecules which operate at this efferent olivocochlear-hair cell synapse,how the synapse operates to fine tune amplification in the inner ear and the role of the efferent systemin protection from acoustic trauma.