Schlösser B, Klausa G, Prime G, Ten Bruggencate G
Institute of Physiology, University of Munich, Germany.
J Comp Neurol. 1999 Mar 8;405(2):185-98. doi: 10.1002/(sici)1096-9861(19990308)405:2<185::aid-cne4>3.0.co;2-b.
On the basis of cytochemical and morphologic differences, two classes of gamma-aminobutyric acidergic (GABAergic) interneurons expressing calcium-binding proteins have been identified in the striatum of adult animals: neurons expressing either parvalbumin (PV) or calretinin (CR). The function of these calcium-binding proteins is not clear, however, they are associated with distinct classes of inhibitory interneurons within the adult neostriatum. By using immunocytochemical techniques, we analyzed the postnatal maturation and the spatiotemporal distribution of PV- and CR-positive neurons in the rat neostriatum compared with a third class of interneurons characterized by the expression of the acetylcholine-synthesizing enzyme, choline acetyltransferase (ChAT). PV-positive cells appeared initially on postnatal day 9 in the lateral region of the striatum. During postnatal weeks 2 and 3, the numbers of PV-positive neurons increased, and this cell population spread progressively in a lateromedial direction. In contrast, CR-expressing neurons were present at birth. During the first few days after birth, the number of CR-immunoreactive cells increased, reaching a peak on postnatal day 5 before declining during the following 2 weeks. A mediolateral gradient was evident temporarily. ChAT-containing neurons were detectable at birth in the lateral striatum. During postnatal weeks 1 and 2, the neurons matured along a lateral-to-medial gradient. The results indicate that the maturation of striatal interneurons is regulated differentially during postnatal development, resulting in a distinct spatiotemporal genesis of phenotypes. The sequential expression of CR and PV suggests a stage-dependent development of subsets of inhibitory interneurons and, hence, the stage-dependent maturation of functionally distinct inhibitory circuits within the neostriatum.
基于细胞化学和形态学差异，在成年动物的纹状体中已鉴定出两类表达钙结合蛋白的γ-氨基丁酸能（GABA能）中间神经元：表达小白蛋白（PV）或钙视网膜蛋白（CR）的神经元。然而，这些钙结合蛋白的功能尚不清楚，它们与成年新纹状体内不同类型的抑制性中间神经元相关。通过免疫细胞化学技术，我们分析了大鼠纹状体中PV和CR阳性神经元的出生后成熟过程以及时空分布，并与以乙酰胆碱合成酶胆碱乙酰转移酶（ChAT）表达为特征的第三类中间神经元进行了比较。PV阳性细胞最初在出生后第9天出现在纹状体的外侧区域。在出生后第2周和第3周，PV阳性神经元的数量增加，并且这一细胞群体逐渐向内外侧方向扩散。相比之下，表达CR的神经元在出生时就已存在。在出生后的头几天，CR免疫反应性细胞的数量增加，在出生后第5天达到峰值，随后在接下来的2周内下降。暂时出现了一个内外侧梯度。含ChAT的神经元在出生时可在外侧纹状体中检测到。在出生后第1周和第2周，这些神经元沿外侧到内侧的梯度成熟。结果表明，纹状体中间神经元的成熟在出生后发育过程中受到不同的调节，导致了表型在时空上的独特发生。CR和PV的顺序表达表明抑制性中间神经元亚群的发育具有阶段依赖性，因此新纹状体内功能不同的抑制性回路的成熟也具有阶段依赖性。
