Kita H, Kita T
Department of Anatomy and Neurobiology, The University of Tennessee Memphis, Memphis, Tennessee 38163, USA.
J Comp Neurol. 2001 Sep 3;437(4):438-48. doi: 10.1002/cne.1294.
The dorsal globus pallidus (GP) receives major inputs from the dorsal neostriatum (Str), the subthalamic nucleus (STN) and the dorsal thalamus. The GP projects to multiple basal ganglia nuclei. One of the GP projection sites is the Str. The pallidostriatal projection has been considered minor. However, several recent studies have suggested that this projection is heavier than previously thought and that it might play a significant role in controlling the activity of the Str. To reveal more details of this projection, we examined the number of GP neurons that participated in the projection, their origins in the GP and their immunoreactivity for the calcium binding protein parvalbumin (PV), by using a combination of Fluoro-Gold (FG) retrograde labeling and immunohistochemical methods. Immunostaining for the calcium binding protein calbindin-28K (CaBP) was used to identify the CaBP-poor sensorimotor and CaBP-rich associative Str regions and the corresponding CaBP-poor middle, CaBP-rich border, and the caudomedial GP regions. The CaBP-poor dorsolateral Str region occupies a small portion of the Str, whereas the CaBP-poor middle GP region occupies a large portion of the GP. The immunostaining for neuron-specific nuclear protein (NeuN) was used to visualize neurons that were immunonegative for FG or PV. Cell counts revealed that the middle GP region contained a higher density of neurons and also a higher percentage of PV-positive neurons than the border and caudomedial regions of the GP. These observations suggested that the GP is involved more in sensorimotor function than associative function. Approximately 40% of neurons in the CaBP-poor middle GP region project to the CaBP-poor part of the dorsolateral Str. Approximately 30% of the neurons in both the CaBP-rich border and the caudomedial GP regions project to the CaBP-rich Str region. More than 40% of the pallidostriatal neurons in CaBP-poor middle GP region are PV-positive, whereas most of those in CaBP-rich GP regions are PV-negative. It was estimated from the cell count data that most of the PV-negative neurons in all three regions of the GP project to the Str. The results indicate that the sensorimotor and associative territories of the Str have reciprocal projections between corresponding territories of the GP. The involvement of a large number of GP neurons suggested that the pallidostriatal projection should be taken into account in the analysis of functional roles of the basal ganglia.
苍白球背侧部（GP）接收来自新纹状体背侧部（Str）、丘脑底核（STN）和背侧丘脑的主要输入。GP投射到多个基底神经节核团。GP的投射部位之一是Str。苍白球-纹状体投射一直被认为是次要的。然而，最近的几项研究表明，这种投射比以前认为的更强，并且可能在控制Str的活动中发挥重要作用。为了揭示这种投射的更多细节，我们结合荧光金（FG）逆行标记和免疫组织化学方法，研究了参与该投射的GP神经元数量、它们在GP中的起源以及它们对钙结合蛋白小白蛋白（PV）的免疫反应性。使用钙结合蛋白钙结合蛋白-28K（CaBP）的免疫染色来识别CaBP含量低的感觉运动和CaBP含量高的联合Str区域以及相应的CaBP含量低的中部、CaBP含量高的边界和尾内侧GP区域。CaBP含量低的背外侧Str区域仅占Str的一小部分，而CaBP含量低的中部GP区域占GP的大部分。使用神经元特异性核蛋白（NeuN）的免疫染色来可视化对FG或PV免疫阴性的神经元。细胞计数显示，与GP的边界和尾内侧区域相比，中部GP区域的神经元密度更高，PV阳性神经元的百分比也更高。这些观察结果表明，GP更多地参与感觉运动功能而非联合功能。CaBP含量低的中部GP区域中约40%的神经元投射到背外侧Str的CaBP含量低的部分。CaBP含量高的边界和尾内侧GP区域中约30%的神经元投射到CaBP含量高的Str区域。CaBP含量低的中部GP区域中超过40%的苍白球-纹状体神经元是PV阳性的，而CaBP含量高的GP区域中的大多数神经元是PV阴性的。根据细胞计数数据估计，GP所有三个区域中的大多数PV阴性神经元都投射到Str。结果表明，Str的感觉运动和联合区域与GP的相应区域之间存在相互投射。大量GP神经元的参与表明，在分析基底神经节的功能作用时应考虑苍白球-纹状体投射。
