Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea.
Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea.
Sci Rep. 2017 Jul 18;7(1):5671. doi: 10.1038/s41598-017-05929-2.
Spike-timing-dependent plasticity (STDP) is considered critical to learning and memory functions in the human brain. Across various types of synapse, STDP is observed as different profiles of Hebbian and anti-Hebbian learning rules. However, the specific roles of diverse STDP profiles in memory formation still remain elusive. Here, we show that the symmetry of the learning rate profile in STDP is crucial to determining the character of stored memory. Using computer simulations, we found that an asymmetric learning rate generates flexible memory that is volatile and easily overwritten by newly appended information. Moreover, a symmetric learning rate generates stable memory that can coexist with newly appended information. In addition, by combining these two conditions, we could realize a hybrid memory type that operates in a way intermediate between stable and flexible memory. Our results demonstrate that various attributes of memory functions may originate from differences in the synaptic stability.
译文： 时程依赖型可塑性（STDP）被认为对人类大脑的学习和记忆功能至关重要。在各种类型的突触中，STDP 表现为不同的赫布和反赫布学习规则的模式。然而，多样化的 STDP 模式在记忆形成中的具体作用仍然难以捉摸。在这里，我们表明 STDP 中学习率曲线的对称性对于确定存储记忆的特征至关重要。通过计算机模拟，我们发现非对称的学习率产生灵活的记忆，这种记忆易变，容易被新附加的信息覆盖。此外，对称的学习率产生稳定的记忆，它可以与新附加的信息共存。此外，通过结合这两种情况，我们可以实现一种混合记忆类型，其工作方式介于稳定记忆和灵活记忆之间。我们的结果表明，记忆功能的各种属性可能源于突触稳定性的差异。
