Fusion pores with low conductance are cation selective.

Cell Rep

School of Applied & Engineering Physics, Cornell University, 142 Sciences Drive, Ithaca, NY 14853, USA; Nanoscale Cell Biology Group, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany. Electronic address:

Published: August 2021

Many neurotransmitters are organic ions that carry a net charge, and their release from secretory vesicles is therefore an electrodiffusion process. The selectivity of early exocytotic fusion pores is investigated by combining electrodiffusion theory, measurements of amperometric foot signals from chromaffin cells with anion substitution, and molecular dynamics simulation. The results reveal that very narrow fusion pores are cation selective, but more dilated fusion pores become anion permeable. The transition occurs around a fusion pore conductance of ∼300 pS. The cation selectivity of a narrow fusion pore accelerates the release of positively charged transmitters such as dopamine, noradrenaline, adrenaline, serotonin, and acetylcholine, while glutamate release may require a more dilated fusion pore.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8500334PMC
http://dx.doi.org/10.1016/j.celrep.2021.109580DOI Listing

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