近日，美国斯坦福大学Karl Deisseroth团队发现皮质层特异性动态触发感知行为。2019年8月9日出版的《科学》发表了这项成果。

感知经历可能源于哺乳动物新皮质中的神经元活动模式。研究人员使用红移通道视紫红质（ChRmine，通过结构导向的基因组挖掘发现）和多路复用多光子全息（MultiSLM）在视觉辨别期间检测小鼠新皮质，实现跨越皮质体积对单独指定神经元的、具有毫秒精度的控制。对一定数量的刺激导向选择神经元进行刺激，可以推动功能相关神经元的广泛招募，这是一个由方位辨别任务学习所加强（但不需要）的过程。方向选择神经元的光遗传靶向操作可引起正确的辨别行为。皮质层特异的动态变化是明显的，因为突出的神经元活动从第2、3层不对称地传播到第5层，并且较小的第5层在引发方向辨别行为方面与较大的第2、3层一样有效。光遗传学刺激后出现的群体动态正确地预测了行为，并且类似于在皮质体积的细胞分辨率下视觉刺激的自然内部表征。

附：英文原文

Title: Cortical layer–specific critical dynamics triggering perception

Author: James H. Marshel, Yoon Seok Kim, Timothy A. Machado, Sean Quirin, Brandon Benson, Jonathan Kadmon, Cephra Raja, Adelaida Chibukhchyan, Charu Ramakrishnan, Masatoshi Inoue, Janelle C. Shane, Douglas J. McKnight, Susumu Yoshizawa, Hideaki E. Kato, Surya Ganguli, Karl Deisseroth

Issue&Volume: Vol. 365, Issue 6453, eaaw5202

Abstract: Perceptual experiences may arise from neuronal activity patterns in mammalian neocortex. We probed mouse neocortex during visual discrimination using a red-shifted channelrhodopsin (ChRmine, discovered through structure-guided genome mining) alongside multiplexed multiphoton-holography (MultiSLM), achieving control of individually specified neurons spanning large cortical volumes with millisecond precision. Stimulating a critical number of stimulus-orientation-selective neurons drove widespread recruitment of functionally related neurons, a process enhanced by (but not requiring) orientation-discrimination task learning. Optogenetic targeting of orientation-selective ensembles elicited correct behavioral discrimination. Cortical layer–specific dynamics were apparent, as emergent neuronal activity asymmetrically propagated from layer 2/3 to layer 5, and smaller layer 5 ensembles were as effective as larger layer 2/3 ensembles in eliciting orientation discrimination behavior. Population dynamics emerging after optogenetic stimulation both correctly predicted behavior and resembled natural internal representations of visual stimuli at cellular resolution over volumes of cortex.

DOI: 10.1126/science.aaw5202

Source: https://science.sciencemag.org/content/365/6453/eaaw5202