| First Author | Jean P | Year | 2018 |
| Journal | Elife | Volume | 7 |
| PubMed ID | 29328020 | Mgi Jnum | J:256848 |
| Mgi Id | MGI:6116919 | Doi | 10.7554/eLife.29275 |
| Citation | Jean P, et al. (2018) The synaptic ribbon is critical for sound encoding at high rates and with temporal precision. Elife 7:e29275 |
| abstractText | We studied the role of the synaptic ribbon for sound encoding at the synapses between inner hair cells (IHCs) and spiral ganglion neurons (SGNs) in mice lacking RIBEYE (RBE(KO/KO)). Electron and immunofluorescence microscopy revealed a lack of synaptic ribbons and an assembly of several small active zones (AZs) at each synaptic contact. Spontaneous and sound-evoked firing rates of SGNs and their compound action potential were reduced, indicating impaired transmission at ribbonless IHC-SGN synapses. The temporal precision of sound encoding was impaired and the recovery of SGN-firing from adaptation indicated slowed synaptic vesicle (SV) replenishment. Activation of Ca(2+)-channels was shifted to more depolarized potentials and exocytosis was reduced for weak depolarizations. Presynaptic Ca(2+)-signals showed a broader spread, compatible with the altered Ca(2+)-channel clustering observed by super-resolution immunofluorescence microscopy. We postulate that RIBEYE disruption is partially compensated by multi-AZ organization. The remaining synaptic deficit indicates ribbon function in SV-replenishment and Ca(2+)-channel regulation. |
