Phase changes in neuronal postsynaptic spiking due to short term plasticity
Fig 1
Conceptual diagram of the overall model and examples of different synaptic configurations.
As shown in Subfigure A, we assume a total of M independent pre-synaptic neurons each make multiple synaptic contacts with a post-synaptic neuron. We refer to each pre-synaptic neuron as forming a single active-zone, and assume each active zone has NM sites that each probabilistically release a single-vesicle when activated by a pre-synaptic action-potential, if one is available at that site. The post-synaptic neuron is assumed to be depolarized by arrival of neurotransmitter resulting from release of vesicles, according to standard models of AMPA receptors. Subfigure B shows a total of N = 512 vesicle release sites are equally distributed between M active zones. Each active zone is the target of a single presynaptic axon (arrows) being driven by a unique input neuron. We refer to the case of a single active zone (M = 1) as the “giant” synaptic pathway, and the case of 512 active zones (M = 512) as the “cortical” synaptic pathway.