Auditory central gain compensates for changes in cochlear output after prolonged low-level noise exposure

ASIAIR > College of Medical and Health Science > Department of Audiology and Speech Pathology, > journal paper > Item 310904400/111936

Please use this identifier to cite or link to this item: http://asiair.asia.edu.tw/ir/handle/310904400/111936

Title:	Auditory central gain compensates for changes in cochlear output after prolonged low-level noise exposure
Authors:	Sheppar, Adam;Sheppard, Adam;Liu, Xiaopeng;Liu, Xiaopeng;Ding, Dalian;Ding, Dalian;Richard, J .;Salvi, Richard J.
Contributors:	聽力暨語言治療學系
Date:	2018-11
Issue Date:	2019-09-02 07:12:43 (UTC+0)
Abstract:	Remarkably, the central auditory system can modify the strength of its sound-evoked neural response based on prior acoustic experiences, a phenomenon referred to as central gain. Gain changes are well documented following traumatic noise exposure, but much less is known about central gain dynamics following prolonged exposure to low-level noise, a common acoustic experience in many urban and work environments. We recently reported that the neural output of the cochlea is reduced, while gain was enhanced in the inferior colliculus (IC) following a 5-week exposure to 75 dB noise. To determine if similar effects were present at even lower intensities, we exposed rats to a 65 dB noise expecting to see little to no change in the cochlea or IC. The exposure had little effect on distortion product otoacoustic emissions and did not cause any hair cell loss. However, the amplitude of the CAP, which reflects the neural output of cochlea, was depressed by 50–75%. Surprisingly, neural responses from the IC were enhanced up to 70%, mainly at frequency within the noise exposure band. One-week post-exposure, CAP amplitudes returned to normal at frequencies within or above the exposure band, whereas responses evoked by frequencies below the exposure band were enhanced by more than 80%. In contrast, IC responses below the exposure frequency were depressed 10–20% whereas responses within the exposure frequency band were enhanced 10–20%. Thus, the central auditory system dynamically up- and down-regulates its gain to maintain supra-threshold neural responses within a narrow homeostatic range; a function that likely contributes to the prevention of sounds from being perceived as muffled or too loud.
Relation:	NEUROSCIENCE LETTERS
Appears in Collections:	[Department of Audiology and Speech Pathology,] journal paper

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	309	View/Open

View Licence

Loading...