Gentilucci M, Fogassi L, Luppino G, Matelli M, Camarda R, Rizzolatti G
Istituto di Fisiologia Umana, Universitá di Parma, Italy.
Exp Brain Res. 1988;71(3):475-90. doi: 10.1007/BF00248741.
Two series of experiments are reported in this paper. The first concerns the movement representation in the macaque inferior area 6, the second the functional properties of neurons located in the caudal part of this area (histochemical area F4). By combining single neuron recording and intracortical microstimulation, we found that inferior area 6 is somatotopically organized. The axio-proximal movements are represented caudally, the distal movements are represented near the arcuate sulcus. The mouth field is located laterally, the hand field medially. There is no leg field. A comparison between neuron properties and histochemical characteristics of inferior area 6 showed that the proximal movements representation includes most of area F4, whereas the distal movements representation corresponds to area F5 and to the rostral part of F4. Neurons located in that part of F4 where proximal movements are represented respond very well to tactile stimuli. They have large receptive fields mostly located on the face and on the upper part of the body. A large number of these neurons respond to visual stimuli. Objects approaching the animal are particularly effective. The tactile and the visual receptive fields are in register. The most represented movements are reaching movements, movements bringing the hand to the mouth or to the body and facial movements. There is a congruence between location of visual fields and preferred arm movements. It is argued that the receptive field arrangement and the response properties are more complex in area F4 than in the primary motor cortex and that area F4 neurons are involved in the control of arm movements towards different space sectors.
本文报道了两个系列的实验。第一个实验关注猕猴6区下部的运动表征，第二个实验关注位于该区域尾部（组织化学F4区）的神经元的功能特性。通过结合单神经元记录和皮质内微刺激，我们发现6区下部呈躯体定位组织。近端轴突运动在尾部表征，远端运动在弓形沟附近表征。口部区域位于外侧，手部区域位于内侧。没有腿部区域。对6区下部神经元特性和组织化学特征的比较表明，近端运动表征包括大部分F4区，而远端运动表征对应于F5区和F4区的前部。位于F4区中表征近端运动的那部分区域的神经元对触觉刺激反应良好。它们具有大多位于面部和身体上部的大感受野。这些神经元中有大量对视觉刺激有反应。接近动物的物体特别有效。触觉和视觉感受野是对齐的。最常表征的运动是伸手动作、将手伸向嘴部或身体的动作以及面部动作。视野位置与偏好的手臂动作之间存在一致性。有人认为，F4区的感受野排列和反应特性比初级运动皮层更复杂，并且F4区神经元参与控制手臂向不同空间区域的运动。
