Small arms fire-like noise: Effects on hearing loss, gap detection and the influence of preventive treatment

Publication date: Available online 25 July 2018Source: NeuroscienceAuthor(s): Richard A. Altschuler, Karin Halsey, Ariane Kanicki, Cathy Martin, Diane Prieskorn, Susan DeRemer, David F. DolanAbstractA 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 sign...

Source: Neuroscience - July 25, 2018 Category: Neuroscience Source Type: research