This is the first year for the Section on Sensory Cell Development and Function. Our main focus has been on setting up the lab, training new lab members and and establishing SOPs. The lab now has demonstrated proficiency in several areas: animal husbandry and creation of mutant and transgenic zebrafish, electrophysiology, and rapid, swept-field confocal imaging in zebrafish. Specific accomplishments for this fiscal year include getting approval for our animal protocols, establishing our transgenic and mutant zebrafish colony, setting the groundwork to build our own zebrafish facility, and obtaining preliminary results for our research program. Currently we have established methodology and configured microscopes to image calcium and vesicle release at synaptic ribbons, and to image synaptogenesis and synapse regeneration in vivo. Additionally we have successfully designed effective CRISPRs to knockdown genes required for ribbon synapse function, development and regeneration. Building on this, we have begun testing several mutant zebrafish for phenotypes using these imaging techniques. Lastly, we have established methods to measure postsynaptic activity in hair-cell afferents using electrophysiology and calcium imaging. These latter techniques will complement our pre-synaptic measurements and allow us to ascertain how alterations to synaptic ribbons ultimately affect synaptic transmission.