Unité de Neurosciences, Information et Complexité, UNIC-FRE3693, Centre National de la Recherche Scientifique, Gif sur Yvette, 91198, France.
Nat Commun. 2018 Oct 3;9(1):4053. doi: 10.1038/s41467-018-06585-4.
Tactile perception in rodents depends on simultaneous, multi-whisker contacts with objects. Although it is known that neurons in secondary somatosensory cortex (wS2) respond to individual deflections of many whiskers, wS2's precise function remains unknown. The convergence of information from multiple whiskers into wS2 neurons suggests that they are good candidates for integrating multi-whisker information. Here, we apply stimulation patterns with rich dynamics simultaneously to 24 macro-vibrissae of rats while recording large populations of single neurons. Varying inter-whisker correlations without changing single whisker statistics, we observe pronounced supra-linear multi-whisker integration. Using novel analysis methods, we show that continuous multi-whisker movements contribute to the firing of wS2 neurons over long temporal windows, facilitating spatio-temporal integration. In contrast, primary cortex (wS1) neurons encode fine features of whisker movements on precise temporal scales. These results provide the first description of wS2's representation during multi-whisker stimulation and outline its specialized role in parallel to wS1 tactile processing.
啮齿动物的触觉感知依赖于与物体同时进行的多根触须接触。虽然已知二级体感皮层（wS2）中的神经元会对许多触须的单独偏转做出反应，但 wS2 的确切功能仍不清楚。来自多个触须的信息汇聚到 wS2 神经元中，表明它们是整合多触须信息的良好候选者。在这里，我们同时应用具有丰富动力学的刺激模式来刺激大鼠的 24 根宏观触须，同时记录大量的单个神经元。在不改变单个触须统计数据的情况下，我们观察到明显的超线性多触须整合。使用新的分析方法，我们表明连续的多触须运动有助于 wS2 神经元在长时窗内发射，促进时空整合。相比之下，初级皮层（wS1）神经元在精确的时间尺度上对触须运动的精细特征进行编码。这些结果首次描述了 wS2 在多触须刺激期间的表现，并概述了它在与 wS1 触觉处理平行的特殊作用。
