长时程增强的维持与非双稳态长时程记忆
Modeling Maintenance of Long-Term Potentiation in Clustered Synapses, Long-Term Memory Without Bistability
摘要：
记忆至少有一部分是以强突触的模式储存的。在分子更替的情况下，突触如何在记忆持续存在的岁月里保持强大？一些模型假设生物化学的双稳态维持了强大的突触。然而，双稳态应该给出突触强度或重量的双峰分布，而目前的数据显示重量和相关变量（树突棘体积）的单峰分布。单突触的双稳性也从未被经验证明。因此，模型模拟单峰分布和长期记忆持续性是很重要的。在这里，开发了一个模型，连接正在进行的，竞争过程的突触生长和削弱的随机过程中的受体插入和移除树突棘。该模型模拟长期（超过1年）持久性的强突触组。结果是单峰重量分布。为了这种分布的稳定性，它被证明是必不可少的，将资源竞争组织成小集群的突触之间。在竞争的情况下，这些集群可以稳定多年。这些模拟与最近的数据一致，以支持集群可塑性假说，这表明集群，而不是单一的突触接触，可能是一个基本单位的长期记忆的存储。该模型进行了经验性预测，并可能提供一个框架，以研究保持突触可塑性和记忆稳定性之间的平衡的机制。
英文摘要：
Memories are stored, at least partly, as patterns of strong synapses. Given molecular turnover, how can synapses maintain strong for the years that memories can persist? Some models postulate that biochemical bistability maintains strong synapses. However, bistability should give a bimodal distribution of synaptic strength or weight, whereas current data show unimodal distributions for weights and for a correlated variable, dendritic spine volume. Bistability of single synapses has also never been empirically demonstrated. Thus it is important for models to simulate both unimodal distributions and long-term memory persistence. Here a model is developed that connects ongoing, competing processes of synaptic growth and weakening to stochastic processes of receptor insertion and removal in dendritic spines. The model simulates long-term (in excess of 1 yr) persistence of groups of strong synapses. A unimodal weight distribution results. For stability of this distribution it proved essential to incorporate resource competition between synapses organized into small clusters. With competition, these clusters are stable for years. These simulations concur with recent data to support the clustered plasticity hypothesis, which suggests clusters, rather than single synaptic contacts, may be a fundamental unit for storage of long-term memory. The model makes empirical predictions, and may provide a framework to investigate mechanisms maintaining the balance between synaptic plasticity and stability of memory.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
