Before revision:  The model consists of a pre-synaptic bouton, a post-synaptic dendritic spine head , a synaptic cleft and a perisynaptic astrocyte controlling Ca2+ dynamics inside the synaptic bouton.
After revision:  The model consists of a pre-synaptic bouton, a post-synaptic dendritic spine head , a synaptic cleft and a peri-synaptic astrocyte controlling Ca2+ dynamics inside the synaptic bouton.