The mammalian rod synaptic ribbon is essential for Cav channel facilitation and ultrafast synaptic vesicle fusion
2021 | journal article; research paper. A publication with affiliation to the University of Göttingen.
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Details
- Authors
- Grabner, Chad Paul ; Moser, Tobias
- Abstract
- Rod photoreceptors (PRs) use ribbon synapses to transmit visual information. To signal ‘no light detected’ they release glutamate continually to activate post-synaptic receptors. When light is detected glutamate release pauses. How a rod’s individual ribbon enables this process was studied here by recording evoked changes in whole-cell membrane capacitance from wild-type and ribbonless ( Ribeye -ko) mice. Wild-type rods filled with high (10 mM) or low (0.5 mM) concentrations of the Ca 2+ -buffer EGTA created a readily releasable pool (RRP) of 87 synaptic vesicles (SVs) that emptied as a single kinetic phase with a τ<0.4 ms. The lower concentration of EGTA accelerated Ca v channel opening and facilitated release kinetics. In contrast, ribbonless rods created a much smaller RRP of 22 SVs, and they lacked Ca v channel facilitation; however, Ca 2+ channel-release coupling remained tight. These release deficits caused a sharp attenuation of rod-driven scotopic light responses. We conclude that the synaptic ribbon facilitates Ca 2+ -influx and establishes a large RRP of SVs.
- Issue Date
- 2021
- Journal
- eLife
- Project
- EXC 2067: Multiscale Bioimaging
SFB 1286: Quantitative Synaptologie
SFB 1286 | B05: Quantitative molekulare Physiologie aktiver Zonen in Calyx-Synapsen - Working Group
- RG Moser (Molecular Anatomy, Physiology and Pathology of Sound Encoding)
- eISSN
- 2050-084X
- Language
- English