Researchers at the University Medical Center Göttingen (UMG) and the Göttingen Cluster of Excellence “Multiscale Bioimaging” (MBExC) have shown how a minimal change in a single ion channel increases the sensitivity of sensory cells in the inner ear. Even soft sounds, such as a whisper, are perceived more clearly, but can cause prolonged overloading, which can ultimately lead to long-term hearing loss. These findings deepen our understanding of how sound information is encoded in the ear. The results have been published in the journal “Science Advances”.
Calcium channels of synapses of sensory hair cells couple the sound stimulus to the excitation of the auditory nerve. Compared to the intact CaV1.3 channel (wildtyp, left), the genetically modified CaVAG variant, which is based on a minimal change in the blueprint of the CACNAD1 gene, causes activation of the synapses of sensory hair cells in response to very weak sound stimuli and thus leads to increased auditory nerve activity. The mouse model shows that the increased voltage sensitivity of the channel results in damage to the synapses due to overexcitation even at everyday sound levels. Figure: Karagulyan/Moser.
