Related Experiment Video
Updated: May 7, 2026
Modified Experimental Conditions for Noise-Induced Hearing Loss in Mice and Assessment of Hearing Function and Outer Hair Cell Damage
Published on: February 10, 2023
Protective effect of dexmedetomidine on noise-induced hearing loss
Jian Wen1, Ying Xiao, Yan-Xia Bai
1Department of Anesthesiology (J.W., Y.X.), The First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Xi'an, China.
Objectives/Hypothesis:
Noise generated by instruments, such as mastoid or craniotomy drills, may cause hearing damage by reducing the cochlear blood flow (CoBF). This study investigated whether dexmedetomidine can lessen noise-induced hearing loss (NIHL) in a guinea pig model.
Study Design:
Animal study using noise stimulation and measurement of hearing and CoBF in guinea pigs.
Methods:
Guinea pigs (n = 8 animals/group) were treated by saline vehicle (control group), dexmedetomidine (1, 3, and 10 μg/kg dex groups), saline and noise (noise group), or 3 μg/kg dexmedetomidine and noise (dex+noise group). For noise exposure, octave band noise at 124 dB sound pressure level was administered to animals for 2 hours. Blood pressure (BP) and CoBF were monitored continuously. Auditory function was measured by the auditory brain-stem response (ABR) before and 1 hour, 3 hours, 8 hours, and 10 days after noise exposure. Plasma norepinephrine (NE) was measured at baseline and 30, 60, 90, and 120 minutes after noise exposure by high-performance liquid chromatography (HPLC).
Results:
Noise exposure caused temporary and permanent hearing damage. Dexmedetomidine concentrations of 1 μg/kg and 3 μg/kg dose dependently improved CoBF. Administration of 10 μg/kg dexmedetomidine drastically reduced BP and CoBF. Pretreatment with 3 μg/kg dexmedetomidine alleviated the noise-induced reduction in CoBF and improved hearing function by decreasing the permanent and temporary threshold shifts.
Conclusion:
Dexmedetomidine displayed protective effects against NIHL in this animal model, suppressing activation of the sympathetic nervous system and improving CoBF. These findings could have clinical relevance and deserve further investigation.
