| Cochlear implant use following neonatal deafness influences the cochleotopic organization of the primary auditory cortex in cats. | |
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MedLine Citation:
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PMID: 18972570 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Electrical stimulation of spiral ganglion neurons in a deafened cochlea, via a cochlear implant, provides a means of investigating the effects of the removal and subsequent restoration of afferent input on the functional organization of the primary auditory cortex (AI). We neonatally deafened 17 cats before the onset of hearing, thereby abolishing virtually all afferent input from the auditory periphery. In seven animals the auditory pathway was chronically reactivated with environmentally derived electrical stimuli presented via a multichannel intracochlear electrode array implanted at 8 weeks of age. Electrical stimulation was provided by a clinical cochlear implant that was used continuously for periods of up to 7 months. In 10 long-term deafened cats and three age-matched normal-hearing controls, an intracochlear electrode array was implanted immediately prior to cortical recording. We recorded from a total of 812 single unit and multiunit clusters in AI of all cats as adults using a combination of single tungsten and multichannel silicon electrode arrays. The absence of afferent activity in the long-term deafened animals had little effect on the basic response properties of AI neurons but resulted in complete loss of the normal cochleotopic organization of AI. This effect was almost completely reversed by chronic reactivation of the auditory pathway via the cochlear implant. We hypothesize that maintenance or reestablishment of a cochleotopically organized AI by activation of a restricted sector of the cochlea, as demonstrated in the present study, contributes to the remarkable clinical performance observed among human patients implanted at a young age. |
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Authors:
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James B Fallon; Dexter R F Irvine; Robert K Shepherd |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: The Journal of comparative neurology Volume: 512 ISSN: 1096-9861 ISO Abbreviation: J. Comp. Neurol. Publication Date: 2009 Jan |
Date Detail:
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Created Date: 2008-11-25 Completed Date: 2009-01-15 Revised Date: 2010-08-27 |
Medline Journal Info:
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Nlm Unique ID: 0406041 Medline TA: J Comp Neurol Country: United States |
Other Details:
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Languages: eng Pagination: 101-14 Citation Subset: IM |
Affiliation:
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The Bionic Ear Institute, Melbourne, Victoria, Australia 3002. jfallon@bionicear.org |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Auditory Cortex / anatomy & histology*, physiology Auditory Pathways / anatomy & histology, physiology Auditory Perception / physiology Brain Mapping Cats Child, Preschool Cochlea* / anatomy & histology, physiology Cochlear Implants* Deafness / chemically induced, physiopathology* Electric Stimulation Electrodes, Implanted Electrophysiology Evoked Potentials, Auditory, Brain Stem / physiology Humans Infant, Newborn |
| Grant Support | |
ID/Acronym/Agency:
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HHS-N-263-2007-00053-C//PHS HHS; HHSN263200700053C//PHS HHS; N01 DC031005/DC/NIDCD NIH HHS; N01-DC-3-4005/DC/NIDCD NIH HHS |
| Comments/Corrections | |
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