Details

Autor(en) / Beteiligte

• Casey, Graham R

Titel

Single and Repeated Mild Traumatic Brain Injuries Cause Auditory Dysfunction and Alter Cochlear Structure

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2021

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• Inner ear related symptomology is a well-established consequence of head injuries, including concussions. Despite this, and despite the commonality of mild traumatic brain injuries (mTBIs), particularly among athletes, the acute effects on audition, the effects of repeated mTBIs, and the underlying pathologies remain poorly understood. This report examines several acute changes in the auditory periphery in a novel animal mTBI model to investigate the effects of mTBI on auditory tissues and function. Mice of different background strains (C57Bl/6, CBA/CaJ, and alpha-9 acetylcholine receptor knockout) received single or repeated mild head injuries or sham treatments and underwent testing to record auditory brainstem responses (ABRs) and distortion product otoacoustic emissions (DPOAEs). Post-mortem otopathological assessments were performed to ascertain hair cell survival, synaptic degeneration, or other pathological damage. Injured mice demonstrated changes in DPOAE amplitudes, ABR thresholds and interwave latencies, and reductions in synapses and outer hair cells. This study improves our understanding of the changes to the auditory system after mTBI and identifies factors such as age and injury repetition that affect the phenotypic severity. Our studies demonstrate the critical need for additional work examining the characteristics, mechanisms, and diagnostic utility of mTBI-induced auditory dysfunction so that better treatments and preventative measures can be adopted.