瑞士苏黎世大学Fritjof Helmchen和英国纽卡斯尔大学Abhishek Banerjee小组合作发现，侧眶额叶皮层（OFC）主导感觉皮层重映射。该研究于2020年9月3日在线发表于《自然》。
研究人员研发了针对固定头小鼠的逆向学习任务，使用双光子钙成像监测了外侧OFC的神经元活动，并研究了OFC如何与主要体感皮层（S1）动态相互作用。小鼠学会了区分“去”与“不去”的触觉刺激，并在刺激-奖励偶然性（“规则转换”）逆转时适应其行为。对所有行为阶段单个神经元的纵向成像表明，S1和外侧OFC有明显的结合，S1神经活动反映了初始任务学习，而外侧OFC神经元则对规则转换做出了重要而短暂的反应。
研究人员确定了从横向OFC到S1的直接远程投射，这些投射可以将此活动反馈回S1作为预测值误差。这种自上而下的信号通过在功能上重新映射从而调节奖励敏感神经元亚群中的响应，进而更新了S1中的感觉经历。功能重映射关键取决于自上而下的反馈，因为利用化学遗传方法沉默外侧OFC神经元破坏了逆向学习以及S1的可塑性。
因此，横向OFC与感觉皮层动态的相互作用实现了对值预测至关重要的计算，该计算依赖于先去的经历且基于错误经历，从而为灵活决策提供了必要的可塑性。
据悉，适应性行为主要取决于灵活的决策，在哺乳动物中，该决策中心位于额叶皮层，特别是眶额叶皮层。OFC如何对决策变量进行编码并指导感觉区域来完成适应性行为仍然是未知的关键问题。
附：英文原文
Title: Value-guided remapping of sensory cortex by lateral orbitofrontal cortex
Author: Abhishek Banerjee, Giuseppe Parente, Jasper Teutsch, Christopher Lewis, Fabian F. Voigt, Fritjof Helmchen
Issue&Volume: 2020-09-03
Abstract: Adaptive behaviour crucially depends on flexible decision-making, which in mammals relies on the frontal cortex, specifically the orbitofrontal cortex (OFC)1,2,3,4,5,6,7,8,9. How OFC encodes decision variables and instructs sensory areas to guide adaptive behaviour are key open questions. Here we developed a reversal learning task for head-fixed mice, monitored the activity of neurons of the lateral OFC using two-photon calcium imaging and investigated how OFC dynamically interacts with primary somatosensory cortex (S1). Mice learned to discriminate ‘go’ from ‘no-go’ tactile stimuli10,11 and adapt their behaviour upon reversal of stimulus–reward contingency (‘rule switch’). Imaging individual neurons longitudinally across all behavioural phases revealed a distinct engagement of S1 and lateral OFC, with S1 neural activity reflecting initial task learning, whereas lateral OFC neurons responded saliently and transiently to the rule switch. We identified direct long-range projections from lateral OFC to S1 that can feed this activity back to S1 as value prediction error. This top-down signal updated sensory representations in S1 by functionally remapping responses in a subpopulation of neurons that was sensitive to reward history. Functional remapping crucially depended on top-down feedback as chemogenetic silencing of lateral OFC neurons disrupted reversal learning, as well as plasticity in S1. The dynamic interaction of lateral OFC with sensory cortex thus implements computations critical for value prediction that are history dependent and error based, providing plasticity essential for flexible decision-making.
DOI: 10.1038/s41586-020-2704-z
Source: https://www.nature.com/articles/s41586-020-2704-z
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html
本期文章：《自然》：Online/在线发表
