Praopim LimsakulCharin ModchangMahidol UniversityUniversity of California, San Diego2018-12-112019-03-142018-12-112019-03-142016-07-01EPJ Applied Physics. Vol.75, No.1 (2016)12860050128600422-s2.0-84979911719https://repository.li.mahidol.ac.th/handle/123456789/40939© EDP Sciences, 2016. We investigate the effects of synaptic vesicle geometry on Ca2+ diffusion dynamics in presynaptic terminals using MCell, a realistic Monte Carlo algorithm that tracks individual molecules. By modeling the vesicle as a sphere and an oblate or a prolate spheroid with a reflective boundary, we measure the Ca2+ concentration at various positions relative to the vesicle. We find that the presence of a vesicle as a diffusion barrier modifies the shape of the [Ca2+] microdomain in the vicinity of the vesicle. Ca2+ diffusion dynamics also depend on the distance between the vesicle and the voltage-gated calcium channels (VGCCs) and on the shape of the vesicle. The oblate spheroidal vesicle increases the [Ca2+] up to six times higher than that in the absence of a vesicle, while the prolate spheroidal vesicle can increase the [Ca2+] only 1.4 times. Our results also show that the presence of vesicles that have different geometries can maximally influence the [Ca2+] microdomain when the vesicle is located less than 50 nm from VGCCs.Mahidol UniversityMaterials ScienceArticleSCOPUS10.1051/epjap/2016150299