Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, United Kingdom.
Gatsby Computational Neuroscience Unit, University College London, London, United Kingdom.
Elife. 2020 Jul 6;9:e54139. doi: 10.7554/eLife.54139.
Pyramidal tract neurons (PTNs) within macaque rostral ventral premotor cortex (F5) and (M1) provide direct input to spinal circuitry and are critical for skilled movement control. Contrary to initial hypotheses, they can also be active during action observation, in the absence of any movement. A population-level understanding of this phenomenon is currently lacking. We recorded from single neurons, including identified PTNs, in (M1) (n = 187), and F5 (n = 115) as two adult male macaques executed, observed, or withheld (NoGo) reach-to-grasp actions. F5 maintained a similar representation of grasping actions during both execution and observation. In contrast, although many individual M1 neurons were active during observation, M1 population activity was distinct from execution, and more closely aligned to NoGo activity, suggesting this activity contributes to withholding of self-movement. M1 and its outputs may dissociate initiation of movement from representation of grasp in order to flexibly guide behaviour.
大脑运动前区皮层腹侧部（F5）和初级运动皮层（M1）中的锥体神经元（PTNs）向脊髓回路提供直接输入，对于熟练的运动控制至关重要。与最初的假设相反，在没有任何运动的情况下，它们也可以在动作观察期间活跃。目前，人们对这一现象还缺乏群体水平的认识。我们记录了两只成年雄性猕猴在执行、观察或（不执行）伸手抓握动作时，来自 M1（n=187）和 F5（n=115）单个神经元的活动，包括已识别的 PTNs。F5 在执行和观察过程中都保持了类似的抓握动作表示。相比之下，尽管许多单个 M1 神经元在观察过程中活跃，但 M1 的群体活动与执行不同，更接近不执行的活动，这表明这种活动有助于抑制自我运动。M1 及其输出可能将运动的发起与抓握的表示分离，以灵活地引导行为。
