Computational Modelling of Synaptic Plasticity in the Dentate Gyrus Granule Cell

Abstract

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 usingthe 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 findthat in simpler nearest-neighbour STDP rules, the choice of pairing scheme is critical in achieving the greatest concordance with experiment.