Gating of hair cell Ca 2+ channels governs the activity of cochlear neurons
Year: 2025
Type: article
Abstract: Our sense of hearing processes sound intensities spanning six orders of magnitude. In the ear, postsynaptic spiral ganglion neurons (SGNs) tile this intensity range with their firing rate codes. Presynaptic inner hair cells (IHCs) vary Ca 2+ -influx among their active zones (AZs) diversifying glutamate release and likely contributing to SGN firing diversity. Here we show that low-voltage activation of IHC-Ca 2+ -influx of mice, modeling the human Ca V 1.3 A749G mutation, increases spontaneous SGN-firing and lowers sound threshold. Altered synaptic morphology in Ca V 1.3 A749G/A749G mice already at ambient sound levels of standard mouse husbandry indicates a risk for noise-induced alterations in Ca V 1.3 A749G patients. We conclude that heterogeneous voltage-dependence of Ca V 1.3 activation among IHC-AZs contributes to the diversity of SGN firing for sound intensity coding and synaptic vulnerability.
Source: Science Advances
Language: English
Subfield: Sensory Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $4,500
OpenAlex ID: W4411401723