Self-organized reactivation maintains and reinforces memories despite synaptic turnover
Self-organized reactivation maintains and reinforces memories despite synaptic turnover
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DOI：
10.7554/elife.43717
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发表时间：
2019-05-10
期刊：
影响因子：
7.7
通讯作者：
van Rossum, Mark C. W.
中科院分区：
文献类型：
--
作者：
Fauth, Michael Jan;van Rossum, Mark C. W.
长期记忆被认为存储在皮层神经元网络的突触中。然而，最近的实验报告不断创建和删除皮层突触，这提出了一个问题，记忆如何在这样一个可变的基底上生存。在这里，我们研究的形成和保留的联想记忆在一个计算模型的基础上，赫布细胞组装在突触和结构可塑性的存在。在休息期间，例如可能发生在睡眠期间，组装自发地重新激活，加强记忆，以对抗正在进行的突触移除和替换。在休息期间，每天短暂的重新激活不仅足以维持组装，甚至可以加强组装，并改善模式完成，与实验观察到的离线记忆增益一致。虽然记忆表征内部的连接在休息阶段得到加强，但网络其余部分的连接会衰减并消失，从而调和了睡眠对皮层连接影响的明显相互冲突的假设。
Long-term memories are believed to be stored in the synapses of cortical neuronal networks. However, recent experiments report continuous creation and removal of cortical synapses, which raises the question how memories can survive on such a variable substrate. Here, we study the formation and retention of associative memory in a computational model based on Hebbian cell assemblies in the presence of both synaptic and structural plasticity. During rest periods, such as may occur during sleep, the assemblies reactivate spontaneously, reinforcing memories against ongoing synapse removal and replacement. Brief daily reactivations during rest-periods suffice to not only maintain the assemblies, but even strengthen them, and improve pattern completion, consistent with offline memory gains observed experimentally. While the connectivity inside memory representations is strengthened during rest phases, connections in the rest of the network decay and vanish thus reconciling apparently conflicting hypotheses of the influence of sleep on cortical connectivity.