Formation of feedforward networks and frequency synchrony by spike-timing-dependent plasticity
Formation of feedforward networks and frequency synchrony by spike-timing-dependent plasticity
复制标题
DOI：
10.1007/s10827-007-0022-1
复制
发表时间：
2007-06-01
影响因子：
1.2
通讯作者：
Kori, Hiroshi
中科院分区：
文献类型：
--
作者：
Masuda, Naoki;Kori, Hiroshi
具有不对称学习窗口的峰时相关可塑性(STDP)通常存在于大脑中，对各种基于峰的计算有用，如输入过滤和联想记忆。STDP的一个自然结果是建立因果关系，在某种意义上，神经元在特定的突触前神经元被激发后，学习延迟地激发。STDP对同步性的影响是难以捉摸的，因为峰同步意味着不同神经元之间的单一峰事件，而不是神经元之间的因果延迟关系。我们将探讨STDP如何在带有起搏器的振荡器网络中促进同步。我们证明了具有非对称学习窗口的STDP导致了前馈网络从起搏器开始的自组织。因此，STDP极大地促进了频率同步。尽管由于突触的可塑性，尖峰时间的差异减小了，但有限的时间滞后仍然存在，因此无法实现完美的尖峰同步。与传统的基于耦合神经元相互作用的大规模同步机制不同，这里发现的同步途径是上游神经元奴役下游神经元。对于具有对称学习窗口的STDP，不会发生这种前馈同步的促进。
Spike-timing-dependent plasticity (STDP) with asymmetric learning windows is commonly found in the brain and useful for a variety of spike-based computations such as input filtering and associative memory. A natural consequence of STDP is establishment of causality in the sense that a neuron learns to fire with a lag after specific presynaptic neurons have fired. The effect of STDP on synchrony is elusive because spike synchrony implies unitary spike events of different neurons rather than a causal delayed relationship between neurons. We explore how synchrony can be facilitated by STDP in oscillator networks with a pacemaker. We show that STDP with asymmetric learning windows leads to self-organization of feedforward networks starting from the pacemaker. As a result, STDP drastically facilitates frequency synchrony. Even though differences in spike times are lessened as a result of synaptic plasticity, the finite time lag remains so that perfect spike synchrony is not realized. In contrast to traditional mechanisms of large-scale synchrony based on mutual interaction of coupled neurons, the route to synchrony discovered here is enslavement of downstream neurons by upstream ones. Facilitation of such feedforward synchrony does not occur for STDP with symmetric learning windows.