title: Disruption of lateral olivocochlear neurons with a dopaminergic neurotoxin depresses spontaneous auditory nerve activity.
abstract: Neurons of the lateral olivocochlear (LOC) system project from the auditory brainstem to the cochlea, where they synapse on radial dendrites of auditory nerve fibers. Selective LOC disruption depresses sound-evoked auditory nerve activity in the guinea pig, but enhances it in the mouse. Here, LOC disruption depressed spontaneous auditory nerve activity in the guinea pig. Recordings from single auditory nerve fibers revealed a significantly reduced proportion of fibers with the highest spontaneous firing rates (SRs) and an increased proportion of neurons with lower SRs. Ensemble activity, estimated using round window noise, also decreased after LOC disruption. Decreased spontaneous activity after LOC disruption may be a consequence of reduced tonic release of excitatory transmitters from the LOC terminals in guinea pigs.
authors.affiliation: Department of Speech, Language, and Hearing Sciences, University of Florida, Gainesville, FL 32610 USA. Electronic address: colleeng@phhp.ufl.edu.
authors.forename: Colleen G
authors.initials: CG
authors.lastname: Le Prell
authors.affiliation: Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, MI 48109 USA.
authors.forename: David F
authors.initials: DF
authors.lastname: Dolan
authors.affiliation: Department of Surgery, Southern Illinois University Medical School, Springfield, IL 62794 USA.
authors.forename: Larry F
authors.initials: LF
authors.lastname: Hughes
authors.affiliation: Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, MI 48109 USA.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Altschuler
authors.affiliation: Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, MI 48109 USA.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Shore
authors.affiliation: Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan, Ann Arbor, MI 48109 USA.
authors.forename: Sanford C
authors.initials: SC
authors.lastname: Bledsoe
mesh_terms: D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology*; D000161:Acoustic Stimulation; D000200:Action Potentials; D000818:Animals; D003051:Cochlea / Q000187:drug effects / Q000502:physiology*; D003056:Cochlear Nerve / Q000187:drug effects / Q000502:physiology*; D059290:Dopaminergic Neurons / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006168:Guinea Pigs; D008297:Male; D065832:Superior Olivary Complex / Q000187:drug effects / Q000502:physiology*
chemical_list: D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine
keywords: Auditory nerve; Cochlea; Guinea pig; MPTP; Olivocochlear efferents