Exocytosis at the hair cell ribbon synapse apparently operates without neuronal SNARE proteins

Abstract

International audienceSNARE proteins mediate membrane fusion. Neurosecretion depends on neuronal SNAREs (SNAP-25, syntaxin-1, and synaptobrevin-1 or 2) and is blocked by neurotoxin-mediated cleavage or genetic ablation. We report that exocytosis in mouse inner hair cells (IHCs) is insensitive to neurotoxins and genetic ablation of neuronal SNAREs. We found mRNA but no synaptically localized protein of neuronal SNAREs in IHCs. Thus, IHC exocytosis is unconventional and may operate independently of neuronal SNAREs