Burkitt Anthony N, Meffin Hamish, Grayden David B
The Bionic Ear Institute, East Melbourne, Victoria 3002, Australia.
Neural Comput. 2004 May;16(5):885-940. doi: 10.1162/089976604773135041.
Experimental evidence indicates that synaptic modification depends on the timing relationship between the presynaptic inputs and the output spikes that they generate. In this letter, results are presented for models of spike-timing-dependent plasticity (STDP) whose weight dynamics is determined by a stable fixed point. Four classes of STDP are identified on the basis of the time extent of their input-output interactions. The effect on the potentiation of synapses with different rates of input is investigated to elucidate the relationship of STDP with classical studies of long-term potentiation and depression and rate-based Hebbian learning. The selective potentiation of higher-rate synaptic inputs is found only for models where the time extent of the input-output interactions is input restricted (i.e., restricted to time domains delimited by adjacent synaptic inputs) and that have a time-asymmetric learning window with a longer time constant for depression than for potentiation. The analysis provides an account of learning dynamics determined by an input-selective stable fixed point. The effect of suppressive interspike interactions on STDP is also analyzed and shown to modify the synaptic dynamics.
实验证据表明，突触修饰取决于突触前输入与其所产生的输出尖峰之间的时间关系。在这封信中，给出了尖峰时间依赖可塑性（STDP）模型的结果，其权重动态由一个稳定的不动点决定。根据输入 - 输出相互作用的时间范围，确定了四类STDP。研究了不同输入速率对突触增强的影响，以阐明STDP与经典的长期增强和抑制研究以及基于速率的赫布学习之间的关系。仅在输入 - 输出相互作用的时间范围受输入限制（即限于由相邻突触输入界定的时域）且具有时间不对称学习窗口（抑制的时间常数比增强的时间常数更长）的模型中，发现了高速率突触输入的选择性增强。该分析解释了由输入选择性稳定不动点决定的学习动态。还分析了抑制性尖峰间相互作用对STDP的影响，并表明其会改变突触动态。
