I don't answer that because low-level biology wasn't my realm of expertise even when I still worked in neuroscience. For that I'd defer to the people who wrote

I don't answer that because low-level biology wasn't my realm of expertise even when I still worked in neuroscience. For that I'd defer to the people who wrote this: http://www.scholarpedia.org/article/Short-term_synaptic_plasticity http://www.scholarpedia.org/article/Short-term_synaptic_plas...