The brain speaks back to the ear: molecules, physiology and pathology of the efferent olivocochlear-hair cell synapse

ELGOYHEN AB

Granada

Congreso; Conferencia Leloir XXXVII Congreso, Sociedad Española de Bioquímica y Biología Molecular; 2014

In bringing information about the world to an individual, sensory systems perform a series of common functions. Each system responds with some specificity to a stimulus and each one employs some specialized receptor cells at the periphery to translate specific stimuli into electrical signals that all neurons can use. That initial electrical event begins the process by which the central nervous system constructs an orderly representation of for example, sounds, odors, tastes and objects. Thus, basic sound detection begins when sound waves strike the eardrum, which transmits that physical stimulus to the organ of Corti within the cochlea, the sensory epithelium of the mammalian inner ear. Here the primary receptor cells known as inner hair cells transform the information into electrical signals that are sent to the central nervous system by the auditory nerve. However, unlike vision, touch and the chemical senses, sound processing is modulated by efferent signals that travel in reverse, from the brain back to the inner ear. One fundamental question in auditory neuroscience is what role(s) this feedback plays in our ability to hear. The presentation will overview our work over the years which has contributed 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 system in protection from acoustic trauma.