Yoshida Atsushi, Hikosaka Okihide
Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
bioRxiv. 2023 Jul 28:2023.07.25.550377. doi: 10.1101/2023.07.25.550377.
The indirect pathway of the basal ganglia, including the subthalamic nucleus (STN) and globus pallidus external segment (GPe), is believed to play a crucial role in suppressing involuntary movements. However, recent evidence suggests the STN and GPe also facilitate voluntary movements. This study hypothesized that excitatory inputs from the STN to the GPe contribute to this facilitation, and that excitatory projections to the substantia nigra pars reticulata (SNr) are involved in the inhibition. To disrupt the STN-GPe or STN-SNr projections in monkeys during choice and fixation tasks, glutamate receptor inhibitors were injected into the GPe or SNr, which induced delayed saccade latencies toward good choices in the choice task (GPe) and caused frequent reflexive saccades to objects in the fixation task (SNr). Our findings suggest excitatory inputs to the GPe and SNr work in opposing manners, providing new insights that redefine our understanding of the functions of basal ganglia pathways.
基底神经节的间接通路，包括丘脑底核（STN）和苍白球外侧段（GPe），被认为在抑制不自主运动中起关键作用。然而，最近的证据表明，丘脑底核和苍白球外侧段也促进自主运动。本研究假设，从丘脑底核到苍白球外侧段的兴奋性输入促成了这种促进作用，并且到黑质网状部（SNr）的兴奋性投射参与了抑制作用。为了在猴子进行选择和注视任务期间破坏丘脑底核-苍白球外侧段或丘脑底核-黑质网状部的投射，将谷氨酸受体抑制剂注入苍白球外侧段或黑质网状部，这在选择任务中（苍白球外侧段）导致向良好选择的扫视潜伏期延迟，并在注视任务中（黑质网状部）导致频繁地向物体进行反射性扫视。我们的研究结果表明，对苍白球外侧段和黑质网状部的兴奋性输入以相反的方式起作用，提供了新的见解，重新定义了我们对基底神经节通路功能的理解。
