Variable Effects of Acoustic Trauma on Behavioral and Neural Correlates of Tinnitus In Individual Animals.

Title

Variable Effects of Acoustic Trauma on Behavioral and Neural Correlates of Tinnitus In Individual Animals.

Creator

Longenecker Ryan J; Galazyuk Alexander V

Publisher

Frontiers in behavioral neuroscience

Date

2016
1905-7

Description

The etiology of tinnitus is known to be diverse in the human population. An appropriate animal model of tinnitus should incorporate this pathological diversity. Previous studies evaluating the effect of acoustic over exposure (AOE) have found that animals typically display increased spontaneous firing rates and bursting activity of auditory neurons, which often has been linked to behavioral evidence of tinnitus. However, only a subset of studies directly associated these neural correlates to individual animals. Furthermore, the vast majority of tinnitus studies were conducted on anesthetized animals. The goal of this study was to test for a possible relationship between tinnitus, hearing loss, hyperactivity and bursting activity in the auditory system of individual unanesthetized animals following AOE. Sixteen mice were unilaterally exposed to 116 dB SPL narrowband noise (centered at 12.5 kHz) for 1 h under ketamine/xylazine anesthesia. Gap-induced prepulse inhibition of the acoustic startle reflex (GPIAS) was used to assess behavioral evidence of tinnitus whereas hearing performance was evaluated by measurements of auditory brainstem response (ABR) thresholds and prepulse inhibition PPI audiometry. Following behavioral assessments, single neuron firing activity was recorded from the inferior colliculus (IC) of four awake animals and compared to recordings from four unexposed controls. We found that AOE increased spontaneous activity in all mice tested, independently of tinnitus behavior or severity of threshold shifts. Bursting activity did not increase in two animals identified as tinnitus positive (T+), but did so in a tinnitus negative (T-) animal with severe hearing loss (SHL). Hyperactivity does not appear to be a reliable biomarker of tinnitus. Our data suggest that multidisciplinary assessments on individual animals following AOE could offer a powerful experimental tool to investigate mechanisms of tinnitus.

Subject

inferior colliculus; gap-induced prepulse inhibition of the acoustic startle reflex; hearing loss; prepulse audiometry; single unit recording; tinnitus

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

207–207

Volume

10

Citation

Longenecker Ryan J; Galazyuk Alexander V, “Variable Effects of Acoustic Trauma on Behavioral and Neural Correlates of Tinnitus In Individual Animals.,” NEOMED Bibliography Database, accessed July 23, 2021, https://neomed.omeka.net/items/show/5133.

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