Zenke Friedemann, Agnes Everton J, Gerstner Wulfram
School of Computer and Communication Sciences and School of Life Sciences, Brain-Mind Institute, École Polytechnique Fédérale de Lausanne, Lausanne EPFL 1015, Switzerland.
Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, Porto Alegre RS 91501-970, Brazil.
Nat Commun. 2015 Apr 21;6:6922. doi: 10.1038/ncomms7922.
Synaptic plasticity, the putative basis of learning and memory formation, manifests in various forms and across different timescales. Here we show that the interaction of Hebbian homosynaptic plasticity with rapid non-Hebbian heterosynaptic plasticity is, when complemented with slower homeostatic changes and consolidation, sufficient for assembly formation and memory recall in a spiking recurrent network model of excitatory and inhibitory neurons. In the model, assemblies were formed during repeated sensory stimulation and characterized by strong recurrent excitatory connections. Even days after formation, and despite ongoing network activity and synaptic plasticity, memories could be recalled through selective delay activity following the brief stimulation of a subset of assembly neurons. Blocking any component of plasticity prevented stable functioning as a memory network. Our modelling results suggest that the diversity of plasticity phenomena in the brain is orchestrated towards achieving common functional goals.
突触可塑性被认为是学习和记忆形成的基础，它以各种形式在不同的时间尺度上表现出来。在这里，我们表明，赫布同突触可塑性与快速的非赫布异突触可塑性之间的相互作用，在辅以较慢的稳态变化和巩固过程时，足以在兴奋性和抑制性神经元的脉冲循环网络模型中形成组件并进行记忆回忆。在该模型中，组件在重复的感觉刺激过程中形成，并以强烈的循环兴奋性连接为特征。即使在形成后的数天，尽管网络活动和突触可塑性持续存在，但通过对组件神经元的一个子集进行短暂刺激后的选择性延迟活动，仍可回忆起记忆。阻断可塑性的任何一个组成部分都会阻止其作为记忆网络的稳定运作。我们的建模结果表明，大脑中可塑性现象的多样性是为了实现共同的功能目标而精心安排的。
