title: Type II spiral ganglion afferent neurons drive medial olivocochlear reflex suppression of the cochlear amplifier.
abstract: The dynamic adjustment of hearing sensitivity and frequency selectivity is mediated by the medial olivocochlear efferent reflex, which suppresses the gain of the 'cochlear amplifier' in each ear. Such efferent feedback is important for promoting discrimination of sounds in background noise, sound localization and protecting the cochleae from acoustic overstimulation. However, the sensory driver for the olivocochlear reflex is unknown. Here, we resolve this longstanding question using a mouse model null for the gene encoding the type III intermediate filament peripherin (Prph). Prph((-/-)) mice lacked type II spiral ganglion neuron innervation of the outer hair cells, whereas innervation of the inner hair cells by type I spiral ganglion neurons was normal. Compared with Prph((+/+)) controls, both contralateral and ipsilateral olivocochlear efferent-mediated suppression of the cochlear amplifier were absent in Prph((-/-)) mice, demonstrating that outer hair cells and their type II afferents constitute the sensory drive for the olivocochlear efferent reflex.
authors.affiliation: Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, New South Wales 2052, Australia.
authors.forename: Kristina E
authors.initials: KE
authors.lastname: Froud
authors.affiliation: 1] Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, New South Wales 2052, Australia [2] Departments of Surgery and Neurosciences, University of California San Diego, and Veterans Administration Medical Center, La Jolla, California 92093-0666, USA.
authors.forename: Ann Chi Yan
authors.initials: AC
authors.lastname: Wong
authors.affiliation: Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, New South Wales 2052, Australia.
authors.forename: Jennie M E
authors.initials: JM
authors.lastname: Cederholm
authors.affiliation: Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, New South Wales 2052, Australia.
authors.forename: Matthias
authors.initials: M
authors.lastname: Klugmann
authors.affiliation: 1] Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, New South Wales 2052, Australia [2] Inflammation and Healing Cluster, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland 4558, Australia.
authors.forename: Shaun L
authors.initials: SL
authors.lastname: Sandow
authors.affiliation: Department of Psychiatry and Neuroscience, Laval University, Institut Universitaire en santé mentale de Québec, Quebec, Canada G1J2G3.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Julien
authors.affiliation: Departments of Surgery and Neurosciences, University of California San Diego, and Veterans Administration Medical Center, La Jolla, California 92093-0666, USA.
authors.forename: Allen F
authors.initials: AF
authors.lastname: Ryan
authors.affiliation: Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia, Sydney, New South Wales 2052, Australia.
authors.forename: Gary D
authors.identifier: 000000028413588X
authors.initials: GD
authors.lastname: Housley
mesh_terms: D000818:Animals; D003051:Cochlea / Q000294:innervation / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation; D008297:Male; D051379:Mice; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009475:Neurons, Afferent / Q000502:physiology*; D064531:Peripherins / Q000235:genetics / Q000378:metabolism*; D012018:Reflex / Q000502:physiology*; D013136:Spiral Ganglion / Q000166:cytology* / Q000502:physiology
chemical_list: D064531:Peripherins