Citation

Altschuler RA, Halsey K, Kanicki A, Martin C, Prieskorn D, DeRemer S, Dolan DF. Neuroscience 2019; 407: 32-40.

Affiliation

Kresge Hearing Research Institute, Department of Otolaryngology Head & Neck Surgery, University of Michigan, United States.

Copyright

(Copyright © 2019, International Brain Research Organization, Publisher Elsevier Publishing)

DOI

10.1016/j.neuroscience.2018.07.027

PMID

30053484

Abstract

A noise-induced loss of inner hair cell - auditory nerve synaptic connections has been suggested as a factor that can trigger the progression of maladaptive plastic changes leading to noise-induced tinnitus. The present study used a military relevant small arms fire-like noise (50 biphasic impulses over 2.5 minutes at 152 dB SPL given unilaterally to the right ear) to induce loss (∼1/3) of inner hair cell synaptic ribbons (associated with synapse loss) in rat cochleae with only minor (less than 10%) loss of outer hair cells. Approximately half of the noise-exposed rats showed poorer gap detection post-noise, a behavioral indication suggesting the presence of tinnitus. There was significantly greater loss of inner hair cell ribbons in noise-exposed rats with reduced gap detection compared to noise-exposed rats retaining normal gap detection. We have previously shown systemic administration of piribedil, memantine, and/or ACEMg significantly reduced loss of inner hair cell ribbons induced by a 3 hour 4 kHz octave band 117 dB (SPL) noise. The present study examined if this treatment would also reduce ribbon loss from the small arms fire-like noise exposure and if this would prevent the reduced gap detection. As in the previous study, piribedil, memantine, and ACEMg treatment significantly reduced the noise-induced loss of ribbons, such that it was no longer significantly different from normal. However, it did not prevent development of the reduced gap detection indication of tinnitus in all treated noise exposed rats, reducing the incidence but not reaching significance.

Copyright © 2018. Published by Elsevier Ltd.

Language: en

Keywords

Cochlea; Noise; Synaptopathy; Tinnitus