Microsecond interaural time difference discrimination restored by cochlear implants after neonatal deafness
- University Medical Center Freiburg, Germany
- City University of Hong Kong, Hong Kong
Abstract
Spatial hearing in cochlear implant (CI) patients remains a major challenge with many early deaf users reported to have no measurable sensitivity to interaural time differences (ITDs). Deprivation of binaural experience during an early critical period is often hypothesized to be the cause of this shortcoming. However, we show that neonatally deafened (ND) rats provided with precisely synchronized CI stimulation in adulthood can be trained to lateralize ITDs with essentially normal behavioral thresholds near 50 μs. Furthermore, comparable ND rats show high physiological sensitivity to ITDs immediately after binaural implantation in adulthood. Our result that ND CI rats achieved very good behavioral ITD thresholds while prelingually deaf human CI patients often fail to develop a useful sensitivity to ITD raises urgent questions concerning the possibility that shortcomings in technology or treatment, rather than missing input during early development, may be behind the usually poor binaural outcomes for current CI patients.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files. Data have been deposited to Dryad, under the DOI 10.5061/dryad.573n5tb6d.
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Behavioral and ephys data of research paperDryad Digital Repository, doi:10.5061/dryad.573n5tb6d.
Article and author information
Author details
Nicole Rosskothen-Kuhl
Funding
Deutscher Akademischer Austauschdienst (P.R.I.M.E. - Postdoctoral Researchers International Mobility Experience,REA grant agreement n 605728)
- Nicole Rosskothen-Kuhl
Hong Kong General Research Fund (Hong Kong General Research Fund (11100219))
- Jan W H Schnupp
Deutsche Forschungsgemeinschaft (Cluster of Excellence BrainLinks-BrainTools,Grant number EXC1086)
- Nicole Rosskothen-Kuhl
Taube Kinder lernen hoeren e.V.
- Nicole Rosskothen-Kuhl
Hong Kong (Medical Research Fund (06172296))
- Jan W H Schnupp
Shenzhen Science and Innovation Fund (Shenzhen Science and Innovation Fund (JCYJ20180307124024360))
- Jan W H Schnupp
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All procedures involving experimental animals reported here were approved by the Department of Health of Hong Kong (#16-52 DH/HA&P/8/2/5) or Regierungspräsidium Freiburg (#35-9185.81/G-17/124), as well as by the appropriate local ethical review committee. All surgery was performed under ketamine and xylazine anesthesia, and every effort was made to minimize suffering.
Copyright
© 2021, Rosskothen-Kuhl et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Microsecond interaural time difference discrimination restored by cochlear implants after neonatal deafness
eLife 10:e59300.
https://doi.org/10.7554/eLife.59300
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