We tested the hypothesis that the pallidum contributes to the control of both posture and movement. We recorded neuronal activity from the pallidum in a task in which male cats reached forward from a standing posture to depress a lever. In agreement with previous studies, we found that a majority of pallidal cells (91/116, 78%), including neurons in both the entopeduncular nucleus and the globus pallidus, showed significant modulation of their activity during reaching with the contralateral limb. Mostly different populations of cells were active during the transport (flexion) and lever press (extension) phase of the task. Most cells showed dynamic patterns of activity related to the movement. However, a modest proportion of modulated cells (18/91, 20%) showed properties consistent with a contribution to the control of anticipatory postural responses, whereas a further 10% showed activity consistent with a contribution to postural support during the movement. Although some cells that showed modified activity only during reaches with the contralateral forelimb, many cells (65/91, 71%) were also activated during reaches with the ipsilateral forelimb. This was particularly true for cells related to the lever press, many of which discharged similarly during reaches of either limb. This suggests a context-dependent control of movement and posture in which the same muscles are used for different functions during contralateral and ipsilateral reach. Comparison with the results from recordings made previously from the motor cortex and the pontomedullary reticular formation in the same task show more similarities with the former than the latter.

SIGNIFICANCE STATEMENT Pathologic changes in basal ganglia function frequently lead to problems with postural stability and gait initiation. Here, we show that some neurons in one of the output regions of the basal ganglia, the pallidum, show discharge activity compatible with a contribution to postural control. At the same time, we note that such cells are a minority in this region with most cells being related to movement rather than posture. We also show that many neurons are active during movements of both the contralateral and ipsilateral limbs, sometimes with identical discharge patterns. We suggest that this indicates a context-dependent regulation of movement and posture in the pallidum.

我们测试了苍白球有助于控制姿势和运动的假设。我们在一项任务中记录了苍白球的神经元活动，在该任务中，雄性猫从站立姿势向前伸手压下杠杆。与之前的研究一致，我们发现大多数苍白球细胞 (91/116, 78%)，包括内脚核和苍白球中的神经元，在到达对侧肢体时显示出显着的活动调节。在任务的运输（屈曲）和杠杆按压（伸展）阶段，大部分不同的细胞群是活跃的。大多数细胞显示出与运动相关的动态活动模式。然而，适度比例的调制细胞（18/91，20%) 表现出与对预期姿势反应的控制贡献一致的特性，而另外 10% 表现出与运动期间对姿势支持的贡献一致的活动。尽管一些细胞仅在与对侧前肢接触时显示出改变的活性，但许多细胞 (65/91, 71%) 在与同侧前肢接触时也被激活。对于与杠杆按压相关的细胞尤其如此，其中许多细胞在任一肢体到达时放电相似。这表明对运动和姿势的上下文相关控制，其中相同的肌肉在对侧和同侧伸展期间用于不同的功能。

意义声明基底神经节功能的病理变化经常导致姿势稳定性和步态启动的问题。在这里，我们展示了基底神经节输出区域之一的一些神经元，即苍白球，显示出与对姿势控制的贡献相容的放电活动。同时，我们注意到此类细胞在该区域中是少数，大多数细胞与运动而不是姿势有关。我们还表明，许多神经元在对侧和同侧肢体运动期间都很活跃，有时具有相同的放电模式。我们认为这表明苍白球中运动和姿势的上下文相关调节。