Kakei S, Hoffman D S, Strick P L
Research Service, Veterans Affairs Medical Center, University of Pittsburgh School of Medicine, W1640 Biomedical Science Tower, 200 Lothrop Street, Pittsburgh, Pennsylvania 15261, USA.
Nat Neurosci. 2001 Oct;4(10):1020-5. doi: 10.1038/nn726.
The ventral premotor area (PMv) is a major source of input to the primary motor cortex (M1). To examine the potential hierarchical processing between these motor areas, we recorded the activity of PMv neurons in a monkey trained to perform wrist movements in different directions with the wrist in three different postures. The task dissociated three major variables of wrist movement: muscle activity, direction of joint movement and direction of movement in space. Many PMv neurons were directionally tuned. Nearly all of these neurons (61/65, 94%) were 'extrinsic-like'; they seemed to encode the direction of movement in space independent of forearm posture. These results are strikingly different from results from M1 of the same animal, and suggest that intracortical processing between PMv and M1 may contribute to a sensorimotor transformation between extrinsic and intrinsic coordinate frames.
腹侧运动前区（PMv）是初级运动皮层（M1）的主要输入源。为了研究这些运动区域之间潜在的层级处理过程，我们记录了一只经过训练的猴子的PMv神经元活动，该猴子被训练在手腕处于三种不同姿势时进行不同方向的腕部运动。该任务分离了腕部运动的三个主要变量：肌肉活动、关节运动方向和空间运动方向。许多PMv神经元具有方向调谐特性。几乎所有这些神经元（65个中的61个，94%）都表现为“类外在型”；它们似乎独立于前臂姿势编码空间中的运动方向。这些结果与同一动物M1区的结果显著不同，表明PMv和M1之间的皮层内处理可能有助于外在和内在坐标系之间的感觉运动转换。
