Unilateral conductive hearing loss causes impaired auditory information processing in neurons in the central auditory system

Authors

  • Jennifer L. Thornton University of Colorado School of Medicine, Department of Physiology, Aurora, CO, USA
  • Kelsey L. Anbuhl University of Colorado School of Medicine, Department of Physiology, Aurora, CO, USA
  • Daniel J. Tollin University of Colorado School of Medicine, Department of Physiology, Aurora, CO, USA

Abstract

Temporary conductive hearing loss (CHL) during development and in adults can lead to hearing impairments that persist beyond the CHL. Despite decades of studies, there is little consensus on the mechanisms responsible. Here we introduced 6 weeks of unilateral CHL to adult chinchillas via a foam earplug. Single-unit recordings from inferior colliculus (IC) neurons indicated that the CHL caused a decrease in the efficacy of inhibitory input to the IC contralateral to the earplug and an increase of inhibitory input ipsilateral to the earplug. The changes were seen after removal of the CHL. Sensitivity to interaural-level-difference (ILD) cues to location in IC neurons was shifted by ~10 dB relative to controls. In both ICs, the direction of the shift was consistent with a compensation of the altered ILDs due to the CHL. IC neurons responses carried ~33% less information (mutual information) about ILDs after CHL than normals. Experiments examining cochlear anatomy and peripheral evoked responses confirmed that the results did not arise from damage to the periphery. The CHL-induced shifts of ILD sensitivity suggest a compensatory form of plasticity occurring by at least the level of the IC. The neurons were also impaired in their abilities to encode information about the spatial attributes of sound. How these physiological changes may lead to impaired hearing will be discussed.

References

Dayan, P., and Abbott, L.F. (2001). Theoretical Neuroscience: Computational and Mathematical Modeling of Neural Systems (MIT Press, Cambridge MA).

Jones, H.G., Koka, K., and Tollin, D.J. (2011). “Postnatal development of cochlear microphonic and compound action potentials in a precocious species, chinchilla lanigera,” J. Acoust. Soc. Am., 130, 38-43.

Larsen, E, and Liberman, M.C. (2010). “Contralateral cochlear effects of ipsilateral damage: No evidence for interaural coupling,” Hear. Res., 260, 70-80.

Lupo, J.E., Koka, K., Thornton, J.L., and Tollin, D.J. (2011). “The effects of experimentally induced conductive hearing loss on the spectral and temporal aspects of sound transmission through the ear,” Hear. Res., 272, 30-41.

Moore, D.R., and King, A.J. (2004). “Plasticity of binaural systems,” in Development of the Auditory System, Springer Handbook of Auditory Research. Edited by T.N. Parks, E.W. Rubel, R.R. Fay, and A.N. Popper (Springer-Verlag, New York), pp. 96-172.

Thornton J.L., Chevallier K.M., Koka K., Lupo, J.E., and Tollin, D.J. (2012). “The conductive hearing loss due to an experimentally-induced middle ear effusion alters the interaural level and time difference cues to sound location,” J. Assoc. Res. Otolaryngol., 13, 641-654.

Thornton, J.L., Chevallier, K.M., Koka, K., and Tollin, D.J. (2013). “Conductive hearing loss induced by experimental middle ear effusion in a chinchilla model reveals impaired TM-coupled ossicular chain movement,” J. Assoc. Res. Otolaryngol., 14, 451-464.

Tollin, D.J. (2010). “The development of sound localization mechanisms,” in Oxford Handbook of Developmental Behavioral Neuroscience. Edited by M.S. Blumberg, J.H. Freeman, and S.R. Robinson (Oxford University Press, New York), pp. 262-282.

Whitton, J.P., and Polley, D.B. (2011). “Evaluating the perceptual and pathophysiological consequences of auditory deprivation in early postnatal life: a comparison of basic and clinical studies,” J. Assoc. Res. Otolaryngol. 12, 535-546.

Downloads

Published

2013-12-15

How to Cite

Thornton, J. L., Anbuhl, K. L., & Tollin, D. J. (2013). Unilateral conductive hearing loss causes impaired auditory information processing in neurons in the central auditory system. Proceedings of the International Symposium on Auditory and Audiological Research, 4, 171–178. Retrieved from https://proceedings.isaar.eu/index.php/isaarproc/article/view/2013-18

Issue

Vol. 4 (2013): Auditory Plasticity - Listening with the Brain

Section

2013/3. Plasticity and auditory disorders

License

Authors who publish with this journal agree to the following terms:

a. Authors retain copyright* and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.

b. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.

c. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).

*From the 2017 issue onward. The Danavox Jubilee Foundation owns the copyright of all articles published in the 1969-2015 issues. However, authors are still allowed to share the work with an acknowledgement of the work's authorship and initial publication in this journal.