Data from: Presynaptic Nrxn3 is essential for ribbon-synapse maturation in hair cells

Hair cells of the inner ear and lateral-line system rely on specialized
ribbon synapses to transmit sensory information to the central nervous
system. The molecules required to assemble these synapses are not fully
understood. We show that Nrxn3, a presynaptic adhesion molecule, is
critical for ribbon-synapse maturation in hair cells. In both mouse and
zebrafish models, loss of Nrxn3 results in significantly fewer intact
ribbon synapses. We show in zebrafish that initially, nrxn3 mutants have
normal pre- and post-synapse numbers, but synapses fail to pair, resulting
in postsynapse loss. We also demonstrate that Nrxn3 subtly influences
synapse selectivity in zebrafish lateral-line hair cells that detect
anterior flow. In zebrafish we show that a 60% loss of synapses in nrxn3
mutants dramatically reduces pre- and post-synaptic responses. Despite
fewer synapses, auditory responses in zebrafish and mice are unaffected.
This work demonstrates that Nrxn3 is a critical and conserved molecule
required for the maturation of ribbon synapses. Understanding how ribbon
synapses mature is essential to generating novel therapies to treat
synaptopathies linked to auditory or vestibular dysfunction.