1. SCN11A gene deletion causes sensorineural hearing loss by impairing the ribbon synapses and auditory nerves
- Author
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Shi Li Zhang, Wei Guo Shi, Fei Ji, Yue Zhang, David Z.Z. He, Wei Sun, Shi Ming Yang, Tao Cong, Xin Song, Wei Wei Guo, and Mian Zu
- Subjects
Hearing Loss, Sensorineural ,Stereocilia (inner ear) ,Expression ,Biology ,Ribbon synapse ,lcsh:RC321-571 ,Lesion ,Mice ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,medicine ,otorhinolaryngologic diseases ,Animals ,Auditory system ,Cochlear Nerve ,NAV1.9 Voltage-Gated Sodium Channel ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Cochlea ,030304 developmental biology ,Mice, Knockout ,Mice, Inbred ICR ,0303 health sciences ,Progressive hearing loss ,Hair Cells, Auditory, Inner ,General Neuroscience ,lcsh:QP351-495 ,medicine.disease ,Nav1.9 knockout ,CTBP2 ,Cell biology ,medicine.anatomical_structure ,lcsh:Neurophysiology and neuropsychology ,Synaptopathy ,SGN ,Synapses ,Sensorineural hearing loss ,sense organs ,medicine.symptom ,Gene Deletion ,030217 neurology & neurosurgery ,Research Article ,TTX resistant sodium channels - Abstract
Background The SCN11A gene, encoded Nav1.9 TTX resistant sodium channels, is a main effector in peripheral inflammation related pain in nociceptive neurons. The role of SCN11A gene in the auditory system has not been well characterized. We therefore examined the expression of SCN11A in the murine cochlea, the morphological and physiological features of Nav1.9 knockout (KO) ICR mice. Results Nav1.9 expression was found in the primary afferent endings beneath the inner hair cells (IHCs). The relative quantitative expression of Nav1.9 mRNA in modiolus of wild-type (WT) mice remains unchanged from P0 to P60. The number of presynaptic CtBP2 puncta in Nav1.9 KO mice was significantly lower than WT. In addition, the number of SGNs in Nav1.9 KO mice was also less than WT in the basal turn, but not in the apical and middle turns. There was no lesion in the somas and stereocilia of hair cells in Nav1.9 KO mice. Furthermore, Nav1.9 KO mice showed higher and progressive elevated ABR threshold at 16 kHz, and a significant increase in CAP thresholds. Conclusions These data suggest a role of Nav1.9 in regulating the function of ribbon synapses and the auditory nerves. The impairment induced by Nav1.9 gene deletion mimics the characters of cochlear synaptopathy.
- Published
- 2021