Information Science and Control Engineering, Graduate School of Engineering, Nagaoka University of Technology, 1603-1 Kamitomioka-machi, Nagaoka, Niigata 940-2188, Japan.
Comput Intell Neurosci. 2012;2012:968272. doi: 10.1155/2012/968272. Epub 2012 Dec 30.
Hebbian plasticity precisely describes how synapses increase their synaptic strengths according to the correlated activities between two neurons; however, it fails to explain how these activities dilute the strength of the same synapses. Recent literature has proposed spike-timing-dependent plasticity and short-term plasticity on multiple dynamic stochastic synapses that can control synaptic excitation and remove many user-defined constraints. Under this hypothesis, a network model was implemented giving more computational power to receptors, and the behavior at a synapse was defined by the collective dynamic activities of stochastic receptors. An experiment was conducted to analyze can spike-timing-dependent plasticity interplay with short-term plasticity to balance the excitation of the Hebbian neurons without weight constraints? If so what underline mechanisms help neurons to maintain such excitation in computational environment? According to our results both plasticity mechanisms work together to balance the excitation of the neural network as our neurons stabilized its weights for Poisson inputs with mean firing rates from 10 Hz to 40 Hz. The behavior generated by the two neurons was similar to the behavior discussed under synaptic redistribution, so that synaptic weights were stabilized while there was a continuous increase of presynaptic probability of release and higher turnover rate of postsynaptic receptors.
赫伯氏可塑性精确地描述了两个神经元之间的相关活动如何根据相关活动来增加突触的强度;然而,它无法解释这些活动如何削弱相同突触的强度。最近的文献提出了多个动态随机突触的尖峰时间依赖性可塑性和短期可塑性,这些可塑性可以控制突触兴奋并消除许多用户定义的约束。在这个假设下,实现了一个网络模型,为受体提供了更多的计算能力,并且突触的行为由随机受体的集体动态活动定义。进行了一项实验来分析尖峰时间依赖性可塑性与短期可塑性如何相互作用以平衡赫伯氏神经元的兴奋而没有权重约束?如果是这样,什么潜在的机制有助于神经元在计算环境中保持这种兴奋?根据我们的结果,两种可塑性机制共同作用以平衡神经网络的兴奋,因为我们的神经元稳定了其权重,对于来自 10 Hz 到 40 Hz 的平均发放率的泊松输入。两个神经元产生的行为类似于在突触重新分布下讨论的行为,因此在突触前释放概率持续增加和突触后受体更高的周转率的情况下,突触权重得到稳定。