INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The Medial Olivocochlear System and Protection from Acoustic Trauma
Autor/es:
ELGOYHEN AB
Reunión:
Congreso; TWAS's 23rd General Meeting and 12th General Conference; 2012
Resumen:
The Medial Olivocochlear System and Protection from Acoustic Trauma   Ana Belén Elgoyhen, Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (INGEBI-CONICET), Argentina, elgoyhen@dna.uba.ar   Sound-induced acoustic injury is one of the most common causes of hearing loss and tinnitus. Finding approaches to increase resistance to damage is a research field of great interest. The medial olivocochlear (MOC) pathway provides inhibitory feedback through the release of acetylcholine (ACh) onto outer hair cells (OHCs) of the cochlea, thus reducing cochlear sensitivity. We have explored the participation of the MOC pathway in providing resistance to noise-induced trauma by generating genetically modified mice carrying a mutation in the nicotinic acetylcholine receptor (nAChR) subunit expressed by OHCs. Mutant cells exhibited greater sensitivity to exogenous ACh and prolonged synaptic currents, indicating that the mutation enhanced nAChR function. To determine the consequences of this enhanced receptor function for cochlear responses, we measured auditory brainstem responses and distortion product otoacoustic emissions. The suppression of OHC-mediated amplification produced by stimulating the MOC pathway was enhanced and dramatically prolonged in mutant mice. Moreover, mutant mice had a greater resistance to permanent acoustic injury, indicating that activation of the MOC feedback can protect the inner ear from noise-induced damage. Thus, the efferent pathway provides a promising target for pharmacological prevention of inner ear pathologies derived from acoustic injury, such as hearing loss and tinnitus.