A synaptic F-actin network controls otoferlin-dependent exocytosis in auditory inner hair cells

• Main Authors: Philippe FY Vincent, Yohan Bouleau, Christine Petit, Didier Dulon
• Format: Article
• Language: English
• Published: eLife Sciences Publications Ltd 2015-11-01
• Series: eLife
• Subjects: exocytosis; hair cell; actin network; osmotic pressure
• Online Access: https://elifesciences.org/articles/10988

We show that a cage-shaped F-actin network is essential for maintaining a tight spatial organization of Cav1.3 Ca2+ channels at the synaptic ribbons of auditory inner hair cells. This F-actin network is also found to provide mechanosensitivity to the Cav1.3 channels when varying intracellular hydrostatic pressure. Furthermore, this F-actin mesh network attached to the synaptic ribbons directly influences the efficiency of otoferlin-dependent exocytosis and its sensitivity to intracellular hydrostatic pressure, independently of its action on the Cav1.3 channels. We propose a new mechanistic model for vesicle exocytosis in auditory hair cells where the rate of vesicle recruitment to the ribbons is directly controlled by a synaptic F-actin network and changes in intracellular hydrostatic pressure.