Spontaneous and Partial Repair of Ribbon Synapse in Cochlear Inner Hair Cells After Ototoxic Withdrawal.
Ototoxicity is one of the major causes of sensorineural deafness. However, it remains unclear whether sensorineural deafness is reversible after ototoxic withdrawal. Here, we report that the ribbon synapses between the inner hair cells (IHCs) and spiral ganglion nerve (SGN) fibers can be restored after ototoxic trauma. This corresponds with hearing restoration after ototoxic withdrawal. In this study, adult mice were injected daily with a low dose of gentamicin for 14 consecutive days. Immunostaining for RIBEYE/CtBP2 was used to estimate the number and size of synaptic ribbons in the cochlea. Hearing thresholds were assessed using auditory brainstem responses. Auditory temporal processing between IHCs and SGNs was evaluated by compound action potentials. We found automatic hearing restoration after ototoxicity withdrawal, which corresponded to the number and size recovery of synaptic ribbons, although both hearing and synaptic recovery were not complete. Thus, our study indicates that sensorineural deafness in mice can be reversible after ototoxic withdrawal due to an intrinsic repair of ribbon synapse in the cochlea.
Department of Otolaryngology-Head and Neck Surgery, the Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, 100853, Beijing, China.
Ke
K
Liu
Department of Otolaryngology-Head and Neck Surgery, the Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, 100853, Beijing, China.
DaiShi
D
Chen
Department of Otolaryngology-Head and Neck Surgery, the Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, 100853, Beijing, China.
WeiWei
W
Guo
Department of Otolaryngology-Head and Neck Surgery, the Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, 100853, Beijing, China.
Ning
N
Yu
Department of Otolaryngology-Head and Neck Surgery, the Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, 100853, Beijing, China.
XiaoYu
X
Wang
Department of Otolaryngology-Head and Neck Surgery, the Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, 100853, Beijing, China.
Fei
F
Ji
Department of Otolaryngology-Head and Neck Surgery, the Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, 100853, Beijing, China.
ZhaoHui
Z
Hou
Department of Otolaryngology-Head and Neck Surgery, the Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, 100853, Beijing, China.
Wei-Yan
WY
Yang
Department of Otolaryngology-Head and Neck Surgery, the Institute of Otolaryngology, Chinese PLA General Hospital, 28 Fuxing Road, 100853, Beijing, China. Yangsm301@263.net.
ShiMing
S
Yang
D000200:Action Potentials / Q000187:drug effects*; D000818:Animals; D003051:Cochlea / Q000187:drug effects; D004195:Disease Models, Animal; D004427:Ear Diseases / Q000188:drug therapy*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects; D005260:Female; D005839:Gentamicins / Q000008:administration & dosage* / Q000494:pharmacology*; D006199:Hair Cells, Auditory, Inner / Q000187:drug effects*; D008810:Mice, Inbred C57BL; D013569:Synapses / Q000187:drug effects*
D005839:Gentamicins
Cochlea; Ototoxic exposure; RIBEYE/CtBP2; Ribbon synapse; Sensorineural deafness