Spike timing and firing rate dependent plasticity as calcium-induced transitions in a bistable synapse model

Abstract:

Multiple stimulation protocols have been found to be effective in changing synaptic efficacy by inducing long-term potentiation or depression in the hippocampus and neocortex. In many of those protocols, increases in post-synaptic calcium concentration have been shown to play a crucial role. However, it is still unclear whether and how the dynamics of the post-synaptic calcium concentration alone determine the outcome of synaptic plasticity.

Here, we investigate numerically and analytically a calcium based model of a synapse in which potentation or depression are described by simple calcium thresholds. We show that this model (i) reproduces the diversity of spike-timing dependent plasticity curves observed in different systems, depending on parameters; (ii) reproduces quantitatively a large number of specific protocols involving more complex spike patterns in hippocampal cultures, and hippocampal and cortical slices.