Non-Hebbian Synaptic Plasticity Induced by Repetitive Postsynaptic Action Potentials
Non-Hebbian Synaptic Plasticity Induced by Repetitive Postsynaptic Action Potentials
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DOI：
10.1523/jneurosci.5881-08.2009
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发表时间：
2009-09-09
影响因子：
5.3
通讯作者：
Manabe, Toshiya
中科院分区：
文献类型：
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作者：
Kato, Hiroyuki K.;Watabe, Ayako M.;Manabe, Toshiya
关于记忆储存的现代理论主要集中在Hebbian长时程增强（LTP），其需要突触前和突触后神经元的同时激活来诱导。除了Hebbian LTP，非Hebbian可塑性的作用也被一些神经网络模型预测。然而，仍然只有少数证据已经提出了这种可塑性的存在。在这项研究中，我们表明，在小鼠海马脑片，LTP可以诱导突触后重复去极化单独在突触前输入的情况下。诱导依赖于电压依赖性钙通道而不是NMDA受体（NMDAR），而表达机制与传统的NMDAR依赖性LTP相同。在增强过程中，自发EPSC的幅度增加，这表明这种形式的LTP的一种新的神经元范围的性质。此外，我们还成功地用动作电位序列诱导了LTP，这支持了去极化脉冲诱导的LTP在体内的可能存在。基于这些发现，我们提出了一个模型，在该模型中，神经元范围的LTP与突触特异性赫布可塑性协同工作，以帮助信息加工记忆的形成。
Modern theories on memory storage have mainly focused on Hebbian long-term potentiation (LTP), which requires coincident activation of presynaptic and postsynaptic neurons for its induction. In addition to Hebbian LTP, the roles of non-Hebbian plasticity have also been predicted by some neuronal network models. However, still only a few pieces of evidence have been presented for the presence of such plasticity. In this study, we show in mouse hippocampal slices that LTP can be induced by postsynaptic repetitive depolarization alone in the absence of presynaptic inputs. The induction was dependent on voltage-dependent calcium channels instead of NMDA receptors (NMDARs), whereas the expression mechanism was shared with conventional NMDAR-dependent LTP. During the potentiation, the amplitude of spontaneous EPSCs was increased, suggesting a novel neuron-wide nature of this form of LTP. Furthermore, we also successfully induced LTP with trains of action potentials, which supported the possible existence of depolarizing pulse-induced LTP in vivo. Based on these findings, we suggest a model in which neuron-wide LTP works in concert with synapse-specific Hebbian plasticity to help information processing in memory formation.