| First Author | Frank T | Year | 2010 |
| Journal | Neuron | Volume | 68 |
| Issue | 4 | Pages | 724-38 |
| PubMed ID | 21092861 | Mgi Jnum | J:167745 |
| Mgi Id | MGI:4879068 | Doi | 10.1016/j.neuron.2010.10.027 |
| Citation | Frank T, et al. (2010) Bassoon and the synaptic ribbon organize Ca(2)+ channels and vesicles to add release sites and promote refilling. Neuron 68(4):724-38 |
| abstractText | At the presynaptic active zone, Ca(2)+ influx triggers fusion of synaptic vesicles. It is not well understood how Ca(2)+ channel clustering and synaptic vesicle docking are organized. Here, we studied structure and function of hair cell ribbon synapses following genetic disruption of the presynaptic scaffold protein Bassoon. Mutant synapses--mostly lacking the ribbon--showed a reduction in membrane-proximal vesicles, with ribbonless synapses affected more than ribbon-occupied synapses. Ca(2)+ channels were also fewer at mutant synapses and appeared in abnormally shaped clusters. Ribbon absence reduced Ca(2)+ channel numbers at mutant and wild-type synapses. Fast and sustained exocytosis was reduced, notwithstanding normal coupling of the remaining Ca(2)+ channels to exocytosis. In vitro recordings revealed a slight impairment of vesicle replenishment. Mechanistic modeling of the in vivo data independently supported morphological and functional in vitro findings. We conclude that Bassoon and the ribbon (1) create a large number of release sites by organizing Ca(2)+ channels and vesicles, and (2) promote vesicle replenishment. |
