Multiscale modeling of presynaptic dynamics from molecular to mesoscale
Fig 3
Model of Ca2+-Evoked, Synaptotagmin-Mediated Neurotransmitter Release.
(A,B) Model adapted from Sun et al. [5]. γS and γA represent rates of vesicle fusion from the releasable states of the synchronous and asynchronous mechanisms, respectively. (A) Ca2+-bound states for Syt-1 (synchronous release); Sn indicates n Ca2+ ions bound to the synchronous release mechanism. (B) Ca2+-bound states for Syt-7 (asynchronous release); An indicates n Ca2+ ions bound to the asynchronous release mechanism. (C,D) Action-potential-like stimulus delivered to model axon starting at 0 ms. Diffusion is assumed to be instantaneous, and molecular state probabilities are tracked deterministically over time. (C) Free [Ca2+]i in response to single action potential. (D) Instantaneous vesicle release rate in response to buffered Ca2+ from both synaptotagmin-mediated release mechanisms.