Computational Modelling of Synaptic Plasticity in the Dentate Gyrus Granule Cell

After more than 30 years of study, the dynamics of synaptic plasticity in neurons still remain somewhat a mystery. By conducting a series of simulations on a simulated version of the rat dentate gyrus granule cell using the Izhikevich spiking neuron model, we compare and contrast several potential synaptic plasticity rules' applicability to the same experiment. Based on a 2001 experiment (Abraham et al., 2001), our simulations find that spike timing dependent plasticity (STDP), a more recent (Markram et al., 1997) theory of synaptic plasticity, is insufficient to replicate the heterosynaptic LTD shown in the experiment without including aspects of the significantly older Bienenstock-Cooper-Munro (BCM) (Bienenstock et al., 1982) theory. A combination of the history-independent STDP model and the historydependent BCM model seems most likely to be an accurate candidate for reproducing the greatest variety of cell dynamics. We also find that in simpler nearest-neighbour STDP rules, the choice of pairing scheme is critical in achieving the greatest concordance with experiment.