When shared concept cells support associations: Theory of overlapping memory engrams.
When shared concept cells support associations: Theory of overlapping memory engrams.
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DOI：
10.1371/journal.pcbi.1009691
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发表时间：
2021-12
影响因子：
4.3
通讯作者：
Gerstner W
中科院分区：
文献类型：
--
作者：
Gastaldi C;Schwalger T;De Falco E;Quiroga RQ;Gerstner W
人类内侧颞叶的神经元集合称为概念细胞，编码获得的概念。那些在两个集合体之间共享的概念单元已经被假设为编码概念之间的关联。在这里，我们测试这个假设的计算模型的吸引神经网络。我们发现，在稀疏神经组件编码的概念有一个最小的分数Cmin的神经元之间共享的组件，低于该协会不能可靠地实现;和一个最大的分数Cmax的共享神经元以上的单个概念不能再检索。在存在周期性调制的背景信号（如海马振荡）的情况下，回忆采取联想链的形式，让人想起单词自由回忆理论所假设的那些。迭代神经元生成模型的预测与神经元响应的概念数量的实验数据相匹配。实验证据表明，概念之间的关联是由海马体中神经元组件之间共享的细胞编码的（概念的"重叠"）。什么是确保关联的可靠编码的必要重叠？在什么条件下，联想能够引发概念的同时激活或连锁激活？我们的理论模型表明，理想的重叠提出了一个折衷：重叠应该大于最小值，以可靠地编码关联，但低于最大值，以防止个人记忆的损失。我们的理论解释了来自人类内侧颞叶的实验数据，并提供了一种在抑制存在下链式回忆的机制，同时如果抑制较弱，仍然允许同时回忆。
Assemblies of neurons, called concepts cells, encode acquired concepts in human Medial Temporal Lobe. Those concept cells that are shared between two assemblies have been hypothesized to encode associations between concepts. Here we test this hypothesis in a computational model of attractor neural networks. We find that for concepts encoded in sparse neural assemblies there is a minimal fraction cmin of neurons shared between assemblies below which associations cannot be reliably implemented; and a maximal fraction cmax of shared neurons above which single concepts can no longer be retrieved. In the presence of a periodically modulated background signal, such as hippocampal oscillations, recall takes the form of association chains reminiscent of those postulated by theories of free recall of words. Predictions of an iterative overlap-generating model match experimental data on the number of concepts to which a neuron responds. Experimental evidence suggests that associations between concepts are encoded in the hippocampus by cells shared between neuronal assemblies (“overlap” of concepts). What is the necessary overlap that ensures a reliable encoding of associations? Under which conditions can associations induce a simultaneous or a chain-like activation of concepts? Our theoretical model shows that the ideal overlap presents a tradeoff: the overlap should be larger than a minimum value in order to reliably encode associations, but lower than a maximum value to prevent loss of individual memories. Our theory explains experimental data from human Medial Temporal Lobe and provides a mechanism for chain-like recall in presence of inhibition, while still allowing for simultaneous recall if inhibition is weak.
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影响因子：
16.6
作者：
De Falco, Emanuela;Ison, Matias J.;Fried, Itzhak;Quiroga, Rodrigo Quian
通讯作者：
Quiroga, Rodrigo Quian
影响因子：
3.2
作者：
Recanatesi S;Katkov M;Romani S;Tsodyks M
通讯作者：
Tsodyks M
影响因子：
2.9
作者：
Recanatesi, Stefano;Katkov, Mikhail;Tsodyks, Misha
通讯作者：
Tsodyks, Misha
影响因子：
64.8
作者：
Quiroga, RQ;Reddy, L;Fried, I
通讯作者：
Fried, I
影响因子：
16.2
作者：
Pereira, Ulises;Brunel, Nicolas
通讯作者：
Brunel, Nicolas