Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London WC1N3BG, UK.
Neuron. 2009 Dec 24;64(6):922-30. doi: 10.1016/j.neuron.2009.12.010.
The discovery of "mirror neurons" in area F5 of the ventral premotor cortex has prompted many theories as to their possible function. However, the identity of mirror neurons remains unknown. Here, we investigated whether identified pyramidal tract neurons (PTNs) in area F5 of two adult macaques exhibited "mirror-like" activity. About half of the 64 PTNs tested showed significant modulation of their activity while monkeys observed precision grip of an object carried out by an experimenter, with somewhat fewer showing modulation during precision grip without an object or grasping concealed from the monkey. Therefore, mirror-like activity can be transmitted directly to the spinal cord via PTNs. A novel finding is that many PTNs (17/64) showed complete suppression of discharge during action observation, while firing actively when the monkey grasped food rewards. We speculate that this suppression of PTN discharge might be involved in the inhibition of self-movement during action observation.
腹侧前运动皮层 F5 区“镜像神经元”的发现，引发了许多关于其可能功能的理论。然而，镜像神经元的身份仍然未知。在这里，我们研究了两只成年猕猴 F5 区的已鉴定的皮质脊髓神经元（PTN）是否表现出“镜像样”活动。在观察到实验者进行精确抓握物体的过程中，约一半的 64 个 PTN 表现出其活动的显著调制，而在没有物体或物体被猴子隐藏时进行精确抓握时，显示调制的稍少一些。因此，镜像样活动可以通过 PTN 直接传递到脊髓。一个新的发现是，许多 PTN（64 个中的 17 个）在观察动作时表现出放电完全抑制，而当猴子抓取食物奖励时则积极放电。我们推测，这种 PTN 放电的抑制可能涉及在观察动作时抑制自身运动。
