Unknown

Dataset Information

0

Bassoon and the synaptic ribbon organize Ca²+ channels and vesicles to add release sites and promote refilling.


ABSTRACT: At the presynaptic active zone, Ca²+ influx triggers fusion of synaptic vesicles. It is not well understood how Ca²+ 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. Ca²+ channels were also fewer at mutant synapses and appeared in abnormally shaped clusters. Ribbon absence reduced Ca²+ channel numbers at mutant and wild-type synapses. Fast and sustained exocytosis was reduced, notwithstanding normal coupling of the remaining Ca²+ 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 Ca²+ channels and vesicles, and (2) promote vesicle replenishment.

SUBMITTER: Frank T 

PROVIDER: S-EPMC3005353 | BioStudies | 2010-01-01

REPOSITORIES: biostudies

Similar Datasets

1000-01-01 | S-EPMC4868958 | BioStudies
2017-01-01 | S-EPMC5700815 | BioStudies
1000-01-01 | S-EPMC5700246 | BioStudies
2014-01-01 | S-EPMC4066811 | BioStudies
2018-01-01 | S-EPMC5794258 | BioStudies
1000-01-01 | S-EPMC4210432 | BioStudies
2014-01-01 | S-EPMC6609000 | BioStudies
1000-01-01 | S-EPMC4060678 | BioStudies
2016-01-01 | S-EPMC5025287 | BioStudies
2011-01-01 | S-EPMC3150911 | BioStudies