Modulation of working memory duration by synaptic and astrocytic mechanisms.
Modulation of working memory duration by synaptic and astrocytic mechanisms.
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DOI：
10.1371/journal.pcbi.1010543
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发表时间：
2022-10
影响因子：
4.3
通讯作者：
中科院分区：
文献类型：
--
作者：
突触的短期可塑性和突触前囊泡释放率的调节是许多工作记忆模型的关键组成部分。与此同时，越来越多的研究表明，星形胶质细胞可能通过影响突触传递来调节高级认知功能，如WM。然而，星形胶质细胞信号对WM表达的稳定性和持续时间的影响仍不清楚。在这里，我们介绍了一种缓慢的，活动依赖的星形细胞对WM突触吸引子模型中突触前释放概率的调节。我们比较和分析了一个简单的WM协议在有和没有星形细胞调节的发射速率和尖峰网络中的模拟，并通过分析速率网络中的相空间动力学来支持我们的观察。我们发现，工作记忆表征的持续时间和稳定性受到星形细胞信号和噪声的影响。我们发现星形细胞信号调节WM表征的平均持续时间。此外，如果星形胶质细胞的调节很强，一个缓慢的突触前时间刻度会引入一个“脆弱之窗”，在此期间，WM表征在稳定之前很容易受到噪声的干扰。我们确定了两种机制，通过这两种机制，来自网络中不同来源的噪声可以稳定或破坏WM表示的稳定。我们的研究结果表明：(1)星形细胞的调节对WM的突触吸引子模型中的WM表征的持续时间起着至关重要的决定作用；(2)星形胶质细胞信号可以促进不同的自上而下控制WM表征及其持续时间的机制。形成记忆并回忆它们的能力是我们大脑的迷人特征之一。工作记忆的运作就像一个记忆便签，存储着正在进行的信息，以供进一步处理。在这里，我们提出了一个计算模型，剖析了星形胶质细胞对工作记忆的稳定性和持续时间的影响。我们发现，长的星形细胞时间常数可以影响工作记忆表征的平均持续时间，并产生一个“脆弱窗口”，在此期间，一些记忆被标记为长期存活，而另一些记忆被终止。存活组和终止组的记忆分数可以通过调整星形胶质细胞反馈的强度或其时间常数来调节。这表明星形细胞信号可以被视为自上而下控制工作记忆表征及其持续时间的一种候选机制。
Short-term synaptic plasticity and modulations of the presynaptic vesicle release rate are key components of many working memory models. At the same time, an increasing number of studies suggests a potential role of astrocytes in modulating higher cognitive function such as WM through their influence on synaptic transmission. Which influence astrocytic signaling could have on the stability and duration of WM representations, however, is still unclear. Here, we introduce a slow, activity-dependent astrocytic regulation of the presynaptic release probability in a synaptic attractor model of WM. We compare and analyze simulations of a simple WM protocol in firing rate and spiking networks with and without astrocytic regulation, and underpin our observations with analyses of the phase space dynamics in the rate network. We find that the duration and stability of working memory representations are altered by astrocytic signaling and by noise. We show that astrocytic signaling modulates the mean duration of WM representations. Moreover, if the astrocytic regulation is strong, a slow presynaptic timescale introduces a ‘window of vulnerability’, during which WM representations are easily disruptable by noise before being stabilized. We identify two mechanisms through which noise from different sources in the network can either stabilize or destabilize WM representations. Our findings suggest that (i) astrocytic regulation can act as a crucial determinant for the duration of WM representations in synaptic attractor models of WM, and (ii) that astrocytic signaling could facilitate different mechanisms for volitional top-down control of WM representations and their duration. The ability to form memories and recall them is one of the fascinating features of our brain. Working memory operates like a memory scratch pad storing ongoing information for further processing. Here, we present a computational model dissecting the influence of astrocytes on the stability and duration of working memories. We find that a long astrocytic time constant can influence the mean duration of working memory representations and generate a “window of vulnerability”, during which some memories are tagged for long-term survival while some are terminated. The fraction of memories in the survival and termination groups could be regulated by adjusting the strength of astrocytic feedback or its time constant. This indicates that astrocytic signaling can be viewed as a candidate mechanism for top-down control of working memory representations and their duration.
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影响因子：
56.9
作者：
FUSTER, JM;ALEXANDER, GE
通讯作者：
ALEXANDER, GE
影响因子：
5.3
作者：
Hansel, David;Mato, German
通讯作者：
Mato, German
影响因子：
16.6
作者：
Keune WJ;Hausmann J;Bolier R;Tolenaars D;Kremer A;Heidebrecht T;Joosten RP;Sunkara M;Morris AJ;Matas-Rico E;Moolenaar WH;Oude Elferink RP;Perrakis A
通讯作者：
Perrakis A
DOI：
10.1073/pnas.1316071110
发表时间：
2013-10-08
影响因子：
11.1
作者：
Cortes, Jesus M.;Desroches, Mathieu;Sejnowski, Terrence J.
通讯作者：
Sejnowski, Terrence J.
DOI：
10.1109/81.633888
发表时间：
1997-10-01
期刊：
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-FUNDAMENTAL THEORY AND APPLICATIONS
影响因子：
--
作者：
Freeman, WJ;Chang, HJ;Badler, J
通讯作者：
Badler, J