Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel.
Nat Commun. 2016 Sep 12;7:12740. doi: 10.1038/ncomms12740.
Thalamic inputs of cells in sensory cortices are outnumbered by local connections. Thus, it was suggested that robust sensory response in layer 4 emerges due to synchronized thalamic activity. To investigate the role of both inputs in the generation of correlated cortical activities, we isolated the thalamic excitatory inputs of cortical cells by optogenetically silencing cortical firing. In anaesthetized mice, we measured the correlation between isolated thalamic synaptic inputs of simultaneously patched nearby layer 4 cells of the barrel cortex. Here we report that in contrast to correlated activity of excitatory synaptic inputs in the intact cortex, isolated thalamic inputs exhibit lower variability and asynchronous spontaneous and sensory-evoked inputs. These results are further supported in awake mice when we recorded the excitatory inputs of individual cortical cells simultaneously with the local field potential in a nearby site. Our results therefore indicate that cortical synchronization emerges by intracortical coupling.
感觉皮层细胞的丘脑输入数量超过了局部连接。因此，有人提出，由于丘脑活动的同步，第 4 层会产生强烈的感觉反应。为了研究这两种输入在产生相关皮质活动中的作用，我们通过光遗传学沉默皮质放电来分离皮质细胞的丘脑兴奋性输入。在麻醉的小鼠中，我们测量了同时记录的相邻桶状皮层第 4 层细胞的分离丘脑突触输入之间的相关性。在这里，我们报告说，与完整皮层中兴奋性突触输入的相关活动相反，分离的丘脑输入表现出较低的变异性和异步自发性和感觉诱发输入。当我们在附近的位置同时记录单个皮质细胞的兴奋性输入和局部场电位时，在清醒的小鼠中，这些结果得到了进一步的支持。因此，我们的结果表明，皮质同步是通过皮质内耦合产生的。
