Journal article
Changes in the Response Properties of Inferior Colliculus Neurons Relating to Tinnitus
Frontiers in neurology, Vol.5, pp.203-203
01/01/2014
DOI: 10.3389/fneur.2014.00203
PMCID: PMC4191193
PMID: 25346722
Abstract
Tinnitus is often identified in animal models by using the gap prepulse inhibition of acoustic startle. Impaired gap detection following acoustic over-exposure (AOE) is thought to be caused by tinnitus “filling in” the gap, thus, reducing its salience. This presumably involves altered perception, and could conceivably be caused by changes at the level of the neocortex, i.e., cortical reorganization. Alternatively, reduced gap detection ability might reflect poorer temporal processing in the brainstem, caused by AOE; in which case, impaired gap detection would not be a reliable indicator of tinnitus. We tested the latter hypothesis by examining gap detection in inferior colliculus (IC) neurons following AOE. Seven of nine unilaterally noise-exposed guinea pigs exhibited behavioral evidence of tinnitus. In these tinnitus animals, neural gap detection thresholds (GDTs) in the IC significantly increased in response to broadband noise stimuli, but not to pure tones or narrow-band noise. In addition, when IC neurons were sub-divided according to temporal response profile (onset vs. sustained firing patterns), we found a significant increase in the proportion of onset-type responses after AOE. Importantly, however, GDTs were still considerably shorter than gap durations commonly used in objective behavioral tests for tinnitus. These data indicate that the neural changes observed in the IC are insufficient to explain deficits in behavioral gap detection that are commonly attributed to tinnitus. The subtle changes in IC neuron response profiles following AOE warrant further investigation.
Details
- Title: Subtitle
- Changes in the Response Properties of Inferior Colliculus Neurons Relating to Tinnitus
- Creators
- Joel I. Berger - MRC Institute of Hearing ResearchBen Coomber - MRC Institute of Hearing ResearchTobias T. Wells - MRC Institute of Hearing ResearchMark N. Wallace - MRC Institute of Hearing ResearchAlan R. Palmer - MRC Institute of Hearing Research
- Resource Type
- Journal article
- Publication Details
- Frontiers in neurology, Vol.5, pp.203-203
- Publisher
- Frontiers Media S.A
- DOI
- 10.3389/fneur.2014.00203
- PMID
- 25346722
- PMCID
- PMC4191193
- ISSN
- 1664-2295
- eISSN
- 1664-2295
- Language
- English
- Date published
- 01/01/2014
- Academic Unit
- Neurosurgery
- Record Identifier
- 9984618631502771
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