adaptive and phase selective spike timing dependent plasticity in synaptically coupled neuronal oscillators自适应和相位选择性高峰时间依赖的可塑性synaptically耦合神经元振荡器.pdfVIP

Adaptive and Phase Selective Spike Timing Dependent Plasticity in Synaptically Coupled Neuronal Oscillators Victor Kazantsev1,2*, Ivan Tyukin3 1 Dept of Nonlinear Dynamics, Institute of Applied Physics of RAS, Nizhny Novgorod, Russia, 2 Dept of Neurodynamics and Neurobiology, University of Nizhny Novgorod, Nizhny Novgorod, Russia, 3 Dept of Mathematics, University of Leicester, Leicester, United Kingdom Abstract We consider and analyze the influence of spike-timing dependent plasticity (STDP) on homeostatic states in synaptically coupled neuronal oscillators. In contrast to conventional models of STDP in which spike-timing affects weights of synaptic connections, we consider a model of STDP in which the time lags between pre- and/or post-synaptic spikes change internal state of pre- and/or post-synaptic neurons respectively. The analysis reveals that STDP processes of this type, modeled by a single ordinary differential equation, may ensure efficient, yet coarse, phase-locking of spikes in the system to a given reference phase. Precision of the phase locking, i.e. the amplitude of relative phase deviations from the reference, depends on the values of natural frequencies of oscillators and, additionally, on parameters of the STDP law. These deviations can be optimized by appropriate tuning of gains (i.e. sensitivity to spike-timing mismatches) of the STDP mechanism. However, as we demonstrate, such deviations can not be made arbitrarily small neither by mere tuning of STDP gains nor by adjusting synaptic weights. Thus if accurate phase-locking in the system is required then an additional tuning mechanism is generally needed. We found that adding a very simple adaptation dynamics in the form of slow fluctuations of the base line in the STDP mechanism enables accurate phase tuning in the system with arbitrary high precision. Adaptation operating at a slow time scal