Ulrike Sienknecht and Christine Köppl: Role of the ribbon synapse in high-frequency neural phase locking

In humans and animals with good low-frequency hearing, phase locking by the afferent fibres of the auditory nerve is known to be a salient temporal code for the central auditory system.
This project aims to explore the specific role of the hair-cell ribbon synapse in this process. The chicken is chosen as the model organism because it combines 1) robust auditory-nerve phase-locking into the kHz-range with 2) good accessibility of early embryonic stages in-ovo for established techniques of virus-mediated gene misexpression.
We use chickens with an aberrant phenotype in one ear (generated by virus-mediated gene misexpression) that specifically changes the hair cells and their innervation. We study the consequences for temporal precision of spiking, using different metrics in vivo.
Our bird work complements ongoing work on mouse hair cells by extending the concepts and available toolbox for unravelling the mechanisms for ultrafast processing at this very specialised first synapse in the auditory pathway.

Immunolabelling on a cross-section of the avian (barn owl) basilar papilla. Gray: tall hair cells (labelled by anti-HCS1), Red: presynaptic ribbons (labelled by anti-CtBP2), Cyan: neural terminals (labelled by anti-Na/K-ATPase).