Halim et al. 2026 - Patterned pre-sensory spontaneous activity drives the structural refinement of developing cochlear ribbon synapses

In the mammalian cochlea, hearing relies on highly specialized ribbon-type synapses between sensory inner hair cells (IHCs) and postsynaptic spiral ganglion neurons. During early postnatal maturation, structural and functional refinements re-shape synaptic morphology and thereby maximize release efficiency in the run-up to hearing onset. This developmental period is further characterized by the occurrence of pre-sensory spontaneous activity waves, which are indispensable for the functional maturation of the ascending auditory pathway – yet, its importance for IHC presynaptic structural refinement remains uncertain. Hence, we aimed to assess activity-dependent structural plasticity at cochlear ribbon synapses using genetic, pharmacological and optogenetic approaches. Specifically for this purpose, we developed an optical stimulation device (OSD) to perform customizable long-term and differentially-patterned optogenetic IHC activation under tightly controlled conditions within a standard tissue culture incubator. Our combined data indicate that the dynamic structural plasticity of developing auditory ribbon synapses is activity-dependent.

This repository contains all relevant source data (immunofluorescence analyses, electrophysiological data, 3D print files, etc.) for the published paper.