title: Thin-film micro-electrode stimulation of the cochlea in rats exposed to aminoglycoside induced hearing loss.
abstract: The multi-channel cochlear implant (CI) provides sound and speech perception to thousands of individuals who would otherwise be deaf. Broad activation of auditory nerve fibres when using a CI results in poor frequency discrimination. The CI also provides users with poor amplitude perception due to elicitation of a narrow dynamic range. Provision of more discrete frequency perception and a greater control over amplitude may allow users to better distinguish speech in noise and to segregate sound sources. In this research, thin-film (TF) high density micro-electrode arrays and conventional platinum ring electrode arrays were used to stimulate the cochlea of rats administered sensorineural hearing loss (SNHL) via ototoxic insult, with neural responses taken at 434 multiunit clusters in the central nucleus of the inferior colliculus (CIC). Threshold, dynamic range and broadness of response were used to compare electrode arrays. A stronger current was required to elicit CIC threshold when using the TF array compared to the platinum ring electrode array. TF stimulation also elicited a narrower dynamic range than the PR counterpart. However, monopolar stimulation using the TF array produced more localised CIC responses than other stimulation strategies. These results suggest that individuals with SNHL could benefit from micro stimulation of the cochlea using a monopolar configuration which may provide discrete frequency perception when using TF electrode arrays.
authors.affiliation: School of Psychological Science, La Trobe University, Bundoora, Victoria, 3086, Australia; ARC Centre of Excellence for Electromaterials Science, Australia; Department of Physiology, Monash University, Clayton, 3800, Australia. Electronic address: ben.allitt@monash.edu.
authors.forename: B J
authors.initials: BJ
authors.lastname: Allitt
authors.affiliation: School of Psychological Science, La Trobe University, Bundoora, Victoria, 3086, Australia; ARC Centre of Excellence for Electromaterials Science, Australia.
authors.forename: A R
authors.initials: AR
authors.lastname: Harris
authors.affiliation: School of Psychological Science, La Trobe University, Bundoora, Victoria, 3086, Australia.
authors.forename: S J
authors.initials: SJ
authors.lastname: Morgan
authors.affiliation: School of Psychological Science, La Trobe University, Bundoora, Victoria, 3086, Australia; ARC Centre of Excellence for Electromaterials Science, Australia; Centre for Neural Engineering, University of Melbourne, Australia.
authors.forename: G M
authors.initials: GM
authors.lastname: Clark
authors.affiliation: School of Psychological Science, La Trobe University, Bundoora, Victoria, 3086, Australia; ARC Centre of Excellence for Electromaterials Science, Australia; School of Health Sciences, College of Science Engineering & Health, RMIT University, Bundoora, Australia.
authors.forename: A G
authors.initials: AG
authors.lastname: Paolini
mesh_terms: D000617:Aminoglycosides / Q000009:adverse effects*; D000818:Animals; D001309:Auditory Threshold; D003051:Cochlea / Q000502:physiology / Q000503:physiopathology*; D019929:Cochlear Implantation; D003054:Cochlear Implants; D003056:Cochlear Nerve / Q000502:physiology; D003638:Deafness / Q000534:rehabilitation; D004594:Electrophysiology; D034381:Hearing Loss / Q000139:chemically induced* / Q000601:surgery / Q000628:therapy*; D007245:Inferior Colliculi / Q000187:drug effects; D008297:Male; D008839:Microelectrodes; D051381:Rats; D017208:Rats, Wistar; D012044:Regression Analysis
chemical_list: D000617:Aminoglycosides
keywords: Cochlear implant; Frequency perception; Inferior colliculus; Neural activity; Rat