近日，美国哈佛医学院Wei-Chung Allen Lee等研究人员合作发现，后顶叶皮层中的突触连接基序有助于决策。该研究于2024年2月21日在线发表于国际一流学术期刊《自然》。

研究人员结合虚拟现实行为、双光子钙成像、高通量电子显微镜和电路建模，分析了后顶叶皮层神经元之间的突触连接与其选择性活动的关系。研究人员发现，兴奋性锥体神经元优先以具有相同选择性的抑制性中间神经元为目标。反过来，抑制性中间神经元也会优先攻击具有相反选择性的锥体神经元，从而形成对手抑制模式。即使在不同任务时程中出现活动峰值的神经元之间也存在这种模式。

研究人员建立了由这些基序进行计算的神经回路模型，并发现具有相反选择性的神经群之间的对手抑制会放大选择性输入，从而改善试验类型信息的编码。这些模型还预测，在不同任务时间段出现活动峰值的神经元之间的对手抑制有助于产生特定选择的序列活动。这些结果为大脑皮层回路中的突触连接如何支持学习决策任务提供了证据。

据介绍，在感知决策任务中，后顶叶皮层表现出选择性活动。然而，这种选择性活动是如何从潜在的突触连接中产生的尚不清楚。

附：英文原文

Title: Synaptic wiring motifs in posterior parietal cortex support decision-making

Author: Kuan, Aaron T., Bondanelli, Giulio, Driscoll, Laura N., Han, Julie, Kim, Minsu, Hildebrand, David G. C., Graham, Brett J., Wilson, Daniel E., Thomas, Logan A., Panzeri, Stefano, Harvey, Christopher D., Lee, Wei-Chung Allen

Issue&Volume: 2024-02-21

Abstract: The posterior parietal cortex exhibits choice-selective activity during perceptual decision-making tasks1,2,3,4,5,6,7,8,9,10. However, it is not known how this selective activity arises from the underlying synaptic connectivity. Here we combined virtual-reality behaviour, two-photon calcium imaging, high-throughput electron microscopy and circuit modelling to analyse how synaptic connectivity between neurons in the posterior parietal cortex relates to their selective activity. We found that excitatory pyramidal neurons preferentially target inhibitory interneurons with the same selectivity. In turn, inhibitory interneurons preferentially target pyramidal neurons with opposite selectivity, forming an opponent inhibition motif. This motif was present even between neurons with activity peaks in different task epochs. We developed neural-circuit models of the computations performed by these motifs, and found that opponent inhibition between neural populations with opposite selectivity amplifies selective inputs, thereby improving the encoding of trial-type information. The models also predict that opponent inhibition between neurons with activity peaks in different task epochs contributes to creating choice-specific sequential activity. These results provide evidence for how synaptic connectivity in cortical circuits supports a learned decision-making task.

DOI: 10.1038/s41586-024-07088-7

Source: https://www.nature.com/articles/s41586-024-07088-7