Gregoriou Georgia G, Savaki Helen E
Department of Basic Sciences, Faculty of Medicine, School of Health Sciences, University of Crete, Crete, Greece.
Neuroimage. 2003 Jul;19(3):959-67. doi: 10.1016/s1053-8119(03)00176-9.
Goal-directed reaching requires a precise neural representation of the arm position and the target location. Parietal and frontal cortical areas rely on visual, somatosensory, and motor signals to guide the reaching arm to the desired position in space. To dissociate the regions processing these signals, we applied the quantitative [(14)C]-deoxyglucose method on monkeys reaching either in the light or in the dark. Nonvisual (somatosensory and memory-related) guidance of the arm, during reaching in the dark, induced activation of discrete regions in the parietal, premotor, and motor cortices. These included the dorsal part of the medial bank of the intraparietal sulcus, the ventral premotor area F4, the dorsal premotor area F2 below the superior precentral dimple, and the primary somatosensory and motor cortices. Additional parietal and premotor regions comprising the ventral intraparietal cortex, ventral premotor area F5, and the ventral part of dorsal premotor area F2 were activated by visual guidance of the arm during reaching in the light. This study provides evidence that different regions of the parieto-premotor circuit process the visual, somatosensory, and motor-memory-related signals which guide the moving arm.
目标导向的伸手动作需要精确的手臂位置和目标位置神经表征。顶叶和额叶皮质区域依靠视觉、体感和运动信号将伸手的手臂引导至空间中的期望位置。为了区分处理这些信号的区域，我们对在明视觉或暗视觉条件下伸手的猴子应用了定量[(14)C] - 脱氧葡萄糖法。在黑暗中伸手时，手臂的非视觉（体感和记忆相关）引导会引起顶叶、运动前区和运动皮质中离散区域的激活。这些区域包括顶内沟内侧壁的背侧部分、腹侧运动前区F4、中央前沟上凹陷下方的背侧运动前区F2以及初级体感和运动皮质。在明视觉条件下伸手时，手臂的视觉引导激活了包括腹侧顶内皮质、腹侧运动前区F5和背侧运动前区F2腹侧部分在内的其他顶叶和运动前区。这项研究提供了证据，表明顶叶 - 运动前回路的不同区域处理引导移动手臂的视觉、体感和运动记忆相关信号。
