Takeda Yuto, Hata Katsuhiko, Yamazaki Tokio, Kaneko Masaki, Yokoi Osamu, Tsai Chengta, Umemura Kazuo, Nikuni Tetsuro
Department of Physics, Tokyo University of Science, Tokyo, Japan.
Department of Neuroscience, Research Center for Mathematical Medicine, Tokyo, Japan.
Front Syst Neurosci. 2021 Nov 22;15:771661. doi: 10.3389/fnsys.2021.771661. eCollection 2021.
Synaptic plasticity is vital for learning and memory in the brain. It consists of long-term potentiation (LTP) and long-term depression (LTD). Spike frequency is one of the major components of synaptic plasticity in the brain, a noisy environment. Recently, we mathematically analyzed the frequency-dependent synaptic plasticity (FDP) and found that LTP is more likely to occur with an increase in the frequency of background synaptic activity. Meanwhile, previous studies suggest statistical fluctuation in the amplitude of background synaptic activity. Little is understood, however, about its contribution to synaptic plasticity. To address this issue, we performed numerical simulations of a calcium-based synapse model. Then, we found attenuation of the tendency to become LTD due to an increase in the fluctuation of background synaptic activity, leading to an enhancement of synaptic weight. Our result suggests that the fluctuation affects synaptic plasticity in the brain.
突触可塑性对大脑的学习和记忆至关重要。它由长时程增强（LTP）和长时程抑制（LTD）组成。在嘈杂的大脑环境中，尖峰频率是突触可塑性的主要组成部分之一。最近，我们对频率依赖性突触可塑性（FDP）进行了数学分析，发现随着背景突触活动频率的增加，LTP更有可能发生。同时，先前的研究表明背景突触活动幅度存在统计波动。然而，关于其对突触可塑性的贡献却知之甚少。为了解决这个问题，我们对基于钙的突触模型进行了数值模拟。然后，我们发现由于背景突触活动波动的增加，LTD倾向减弱，导致突触权重增强。我们的结果表明，这种波动会影响大脑中的突触可塑性。
