gms | German Medical Science

Herbsttagung der ADANO 2010

Arbeitsgemeinschaft Deutschsprachiger Audiologen und Neurootologen der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie (ADANO)

16.09. - 17.09.2010, Zürich

Cortical plasticity in unilateral congenital deafness

Meeting Abstract

  • P. Hubka - Institute of Audioneurotechnology & Dept. of Experimental Otology, ENT Clinics Medical University Hannover, Germany
  • J. Tillein - Institute of Audioneurotechnology & Dept. of Experimental Otology, ENT Clinics Medical University Hannover, Germany
  • R. Land - Institute of Audioneurotechnology & Dept. of Experimental Otology, ENT Clinics Medical University Hannover, Germany
  • I. Teudt - Institute of Audioneurotechnology & Dept. of Experimental Otology, ENT Clinics Medical University Hannover, Germany
  • corresponding author A. Kral - Institute of Audioneurotechnology & Dept. of Experimental Otology, ENT Clinics Medical University Hannover, Germany

Arbeitsgemeinschaft Deutschsprachiger Audiologen und Neurootologen der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie. Herbsttagung der ADANO 2010. Zürich, 16.-17.09.2010. Düsseldorf: German Medical Science GMS Publishing House; 2010. Doc10adano03

DOI: 10.3205/10adano03, URN: urn:nbn:de:0183-10adano038

Published: August 25, 2010

© 2010 Hubka et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Previous studies from our lab have shown that sensitivity to interaural time differences (ITD) presented through binaural cochlear implants (CIs) is rudimentary preserved in absence of auditory experience [1], even though the sensitivity to this cue is reduced and cortical aural representation affected by deafness (ibid., [2]). Rare cases in the white cat colony are born with normal unilateral hearing and complete deafness on the other ear. These cases provide an exceptional opportunity for investigation of effects of congenital unilateral (lifelong) experience on sensitivity to electrically-presented binaural cues (through binaural CIs). Approximately 120 unit recordings per animal were obtained from the cortices ipsi- as well as contralateral to the deaf ear. In adult unilaterally-deaf animals, when compared to hearing cats, the same number of responsive units were found (~90%), whereas in binaurally-deaf animals significantly less recording sites (~57%) did respond to CI stimulation. There was, however, less sensitivity to ITD in unilaterally deaf animals than in binaurally deaf animals. Those units that were sensitive to binaural cues in unilaterally-deaf showed no physiological preference to certain binaural parameters, which was different from both binaurally deaf and hearing animals. In consequence, the binaural sensitivity disappeared nearly completely in monaurally deaf animals, despite the fact that non-specific deficits found in binaural deafness were compensated by unilateral hearing.

This demonstrates the extensive and beneficial auditory reorganization in unilaterally deaf that allows to process sensory input by both brain hemispheres; however, at the same time, congenital unilateral deafness has detrimental effects on binaural feature sensitivity and degrades the sensitivity to the deaf ear.

Supported by DFG (Kr 3370/1-1 and 1-2) & MedEl Comp.


References

1.
Tillein J, Hubka P, Syed E, Hartmann R, Engel AK, Kral A. Cortical representation of interaural time difference in congenital deafness. Cereb Cortex. 2010;20(2):492-506. DOI: 10.1093/cercor/bhp222 External link
2.
Kral A, Tillein J, Hubka P, Schiemann D, Heid S, Hartmann R, Engel AK. Spatiotemporal patterns of cortical activity with bilateral cochlear implants in congenital deafness. J Neurosci. 2009;29(3):811-27. DOI: 10.1523/JNEUROSCI.2424-08.2009 External link