Synapse as a Memristor

AbstractThe memristor, the fourth fundamental electric element, was conceptually proposed by L. Chua in 1971 and was found in laboratory late in 2008. Recently a special type of memristor was considered to be able to mimic the behavior of neural synapses. In particular, attributed to the long-term memory of weight changes, the memristor can reproduce the spike-timing-dependent plasticity (STDP) protocol of a synapse, displaying a synaptic modification related to the time interval of pre- and post-synaptic spikes. Not limited to it, we found that the memristor with adaptive thresholds can even mimic higher-order behavior of synapses, realizing the well-known suppression principle of Froemke. This type of memristor can actually express both long-term and short-term plasticities in synapses, which are responsible for the excitation level and the refractory time, respectively. The corresponding dynamical process is governed by a set of ordinary differential equations. Interestingly, the Froemke’s model and our memristor-like model, based on two completely different mechanisms, are found to be quantitatively equivalent. In this chapter we would like to provide this new perspective of looking at synaptic dynamics.KeywordsSynaptic WeightSynaptic ModificationPostsynaptic SpikePresynaptic SpikeSTDP RuleThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.