Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
Department of Biology, Boston University, Boston, MA 02215, USA; Center for Systems Neuroscience, Boston University, Boston, MA 02215, USA.
Neuron. 2020 May 6;106(3):515-525.e5. doi: 10.1016/j.neuron.2020.02.004. Epub 2020 Mar 11.
To interpret the environment, our brain must evaluate external stimuli against internal representations from past experiences. How primary (S1) and secondary (S2) somatosensory cortices process stimuli depending on recent experiences is unclear. Using simultaneous multi-area population imaging of projection neurons and focal optogenetic inactivation, we studied mice performing a whisker-based working memory task. We find that activity reflecting a current stimulus, the recollection of a previous stimulus (cued recall), and the stimulus category are distributed across S1 and S2. Despite this overlapping representation, S2 is important for processing cued recall responses and transmitting these responses to S1. S2 network properties differ from S1, wherein S2 persistently encodes cued recall and the stimulus category under passive conditions. Although both areas encode the stimulus category, only information in S1 is important for task performance through pathways that do not necessarily include S2. These findings reveal both distributed and segregated roles for S1 and S2 in context-dependent sensory processing.
为了解释环境，我们的大脑必须根据过去经验的内部表示来评估外部刺激。初级（S1）和次级（S2）体感皮层如何根据最近的经验处理刺激尚不清楚。我们使用投影神经元的同时多区域群体成像和焦点光遗传失活，研究了在基于胡须的工作记忆任务中执行任务的小鼠。我们发现，反映当前刺激的活动、对先前刺激的回忆（提示回忆）以及刺激类别分布在 S1 和 S2 中。尽管存在这种重叠的表示，但 S2 对于处理提示回忆反应和将这些反应传递到 S1 很重要。S2 的网络特性与 S1 不同，在被动条件下，S2 持续编码提示回忆和刺激类别。尽管两个区域都编码了刺激类别，但只有 S1 中的信息通过不一定包括 S2 的途径对任务表现很重要。这些发现揭示了 S1 和 S2 在上下文相关的感觉处理中既有分布式又有分离的作用。
