PROBABILITY OF ENTRAINMENT, SYNAPTIC MODIFICATION AND ENTRAINED PHASE ARE PHASE-DEPENDENT IN STDP

Abstract

Synaptic conductance can be modified in an activity dependent manner, in which the temporal relationship between pre- and post-synaptic spikes plays a major role. This spike timing dependent plasticity (STDP) has profound implications in neural coding, computation and functionality. Because the STDP learning curve is strongly nonlinear, initial state may have great impacts on the eventual state of the system. However, although this feature is intuitively clear, it has not been explored in detail before. This paper presents a preliminary numerical study in this direction. In a model of two pacemaker neurons and a synapse undergoing STDP, it is found that the probability of entrainment, direction of synaptic modification and entrained phase are all influenced by the initial relative phase. Based on these findings, it is reasonable to propose that the initial-state sensitive feature of STDP may contribute to its role of selective response in oscillatory neural networks.