title: Minocycline protection of neomycin induced hearing loss in gerbils.
abstract: This animal study was designed to determine if minocycline ameliorates cochlear damage is caused by intratympanic injection of the ototoxic aminoglycoside antibiotic neomycin. Baseline auditory-evoked brainstem responses were measured in gerbils that received 40 mM intratympanic neomycin either with 0, 1.2, or 1.5 mg/kg intraperitoneal minocycline. Four weeks later auditory-evoked brainstem responses were measured and compared to the baseline measurements. Minocycline treatments of 1.2 mg/kg and 1.5 mg/kg resulted in significantly lower threshold increases compared to 0 mg/kg, indicating protection of hearing loss between 6 kHz and 19 kHz. Cochleae were processed for histology and sectioned to allow quantification of the spiral ganglion neurons and histological evaluation of organ of Corti. Significant reduction of spiral ganglion neuron density was demonstrated in animals that did not receive minocycline, indicating that those receiving minocycline demonstrated enhanced survival of spiral ganglion neurons, enhanced survival of sensory hairs cells and spiral ganglion neurons, and reduced hearing threshold elevation correlates with minocycline treatment demonstrating that neomycin induced hearing loss can be reduced by the simultaneous application of minocycline.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
authors.forename: Alan M
authors.initials: AM
authors.lastname: Robinson
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
authors.forename: Irena
authors.initials: I
authors.lastname: Vujanovic
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA ; Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA ; Department of Communication Sciences and Disorders, The Hugh Knowles Center, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Claus-Peter
authors.initials: CP
authors.lastname: Richter
mesh_terms: D000818:Animals; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects; D005849:Gerbillinae; D006198:Hair Cells, Auditory / Q000187:drug effects / Q000473:pathology; D034381:Hearing Loss / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D008911:Minocycline / Q000008:administration & dosage*; D009355:Neomycin / Q000009:adverse effects*; D009925:Organ of Corti / Q000187:drug effects / Q000473:pathology; D020011:Protective Agents / Q000008:administration & dosage*
chemical_list: D020011:Protective Agents; D008911:Minocycline; D009355:Neomycin