Clustering and synchronous firing of coupled Rulkov maps with STDP for modeling epilepsy

Epilepsy of the neuropsychiatric disorder is provoked from an imbalance in the long-term potentiation (LTP) versus long-term depression (LTD) of the synapses in the hippocampus. The LTP and LTD are replicated by using the Spike Timing Dependent Plasticity (STDP). Additionally, the spiking activity of the synapses in the hippocampus can be approximated by using the Rulkov maps. In our previous study, we considered some easy simulation models which are constructed by using Rulkov maps with STDP. Moreover, these simulation models consist of unidirectionally coupled neurons. In this paper, we consider some easy simulation models with bidirectionally coupled neurons. We explore the effect of unidirectional and bidirectional connection on spiking activity, as basic simulation for constructing the approximate simulation model of epilepsy. From these results, the unidirectional models show high accuracy in-phase/anti-phase synchronization, and it shows divergent relatively early. The bidirectional models show the stable waveform (i.e., non-divergent) for a long term compared to unidirectional models.