CA3-CA3 recurrent excitatory synapses are thought to play a key role in memory storage and pattern completion. Whether the plasticity properties of these synapses are consistent with their proposed network functions remains unclear. Here, we examine the properties of spike timing-dependent plasticity (STDP) at CA3-CA3 synapses. Low-frequency pairing of excitatory postsynaptic potentials (EPSPs) and action potentials (APs) induces long-term potentiation (LTP), independent of temporal order. The STDP curve is symmetric and broad (half-width ∼150 ms). Consistent with these STDP induction properties, AP-EPSP sequences lead to supralinear summation of spine [Ca(2+)] transients. Furthermore, afterdepolarizations (ADPs) following APs efficiently propagate into dendrites of CA3 pyramidal neurons, and EPSPs summate with dendritic ADPs. In autoassociative network models, storage and recall are more robust with symmetric than with asymmetric STDP rules. Thus, a specialized STDP induction rule allows reliable storage and recall of information in the hippocampal CA3 network.

中文翻译：

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CA3-CA3突触处对称的基于时序时序的可塑性可优化自动关联网络中的存储和调用。

CA3-CA3反复兴奋性突触被认为在记忆存储和模式完成中起关键作用。这些突触的可塑性特性是否与其拟议的网络功能一致尚不清楚。在这里，我们研究了CA3-CA3突触中与峰值时间相关的可塑性（STDP）的特性。兴奋性突触后电位（EPSPs）和动作电位（APs）的低频配对可诱导长期增强（LTP），与时间顺序无关。STDP曲线对称且较宽（半宽约150 ms）。与这些STDP诱导特性一致，AP-EPSP序列导致脊柱[Ca（2+）]瞬态的超线性求和。此外，AP后的去极化（ADP）有效传播到CA3锥体神经元的树突中，EPSP与树突状ADP相加。在自动关联网络模型中，对称的存储和调用比不对称的STDP规则更强大。因此，专用的STDP归纳规则允许在海马CA3网络中可靠地存储和调用信息。