Giménez-Amaya J M, McFarland N R, de las Heras S, Haber S N
Departamento de Morfología, Facultad de Medicina, Universidad Autónoma de Madrid, Spain.
J Comp Neurol. 1995 Mar 27;354(1):127-49. doi: 10.1002/cne.903540109.
Although thalamic projections to the dorsal striatum are well described in primates and other species, little is known about thalamic projections to the ventral or "limbic" striatum in the primate. This study explores the organization of the thalamic projections to the ventral striatum in the primate brain by means of wheat germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) and Lucifer yellow (LY) retrograde tracer techniques. In addition, because functional and connective differences have been described for the core and shell components of the nucleus accumbens in the rat and are thought to be similar in the primate, this study also explores whether these regions of the nucleus accumbens can be distinguished by their thalamic input. Tracer injections are placed in different portions of the ventral striatum, including the medial and lateral regions of the ventral striatum; the central region of the ventral striatum, including the dorsal part of the core of the nucleus accumbens; and the shell region of the nucleus accumbens. Retrogradely labeled neurons are located mainly in the midline nuclear group (anterior and posterior paraventricular, paratenial, rhomboid, and reuniens thalamic nuclei) and in the parafascicular thalamic nucleus. Additional labeled cells are found in other portions of the intralaminar nuclear group as well as in other thalamic nuclei in the ventral, anterior, medial, lateral, and posterior thalamic nuclear groups. The distribution of labeled cells varies depending on the area of the ventral striatum injected. All regions of the ventral striatum receive strong projections from the midline thalamic nuclei and from the parafascicular nucleus. In addition, the medial region of the ventral striatum receives numerous projections from the central superior lateral nucleus, the magnocellular subdivision of the ventral anterior nucleus, and parts of the mediodorsal nucleus. After injection into the lateral region of the ventral striatum, few labeled neurons are seen scattered in nuclei of the intralaminar and ventral thalamic groups and occasional labeled cells in the mediodorsal nucleus. The central region of the ventral striatum, including the dorsal part of the core of the nucleus accumbens, receives a limited projection from the midline thalamic, predominantly from the rhomboid nucleus. It receives much smaller projections from the central medial nucleus and the ventral, anterior, and medial thalamic groups. The shell of the nucleus accumbens receives the most limited projection from the thalamus and is innervated almost exclusively by the midline thalamic nuclei and the central medial and parafascicular nuclei. The shell is distinguished from the rest of the ventral striatum in that it receives the fewest projections from the ventral, anterior, medial, and lateral thalamic nuclei.
虽然在灵长类动物和其他物种中，丘脑向背侧纹状体的投射已有充分描述，但对于灵长类动物中丘脑向腹侧或“边缘”纹状体的投射却知之甚少。本研究通过将小麦胚凝集素与辣根过氧化物酶（WGA-HRP）结合以及荧光黄（LY）逆行示踪技术，探索灵长类动物大脑中丘脑向腹侧纹状体投射的组织结构。此外，由于在大鼠中已描述了伏隔核核心和壳部成分在功能和连接上的差异，并且认为在灵长类动物中也类似，因此本研究还探讨了伏隔核的这些区域是否可通过其丘脑输入来区分。示踪剂注射置于腹侧纹状体的不同部位，包括腹侧纹状体的内侧和外侧区域；腹侧纹状体的中央区域，包括伏隔核核心的背侧部分；以及伏隔核的壳区。逆行标记的神经元主要位于中线核群（前、后室旁核、室旁核、菱形核和连合核）和束旁丘脑核。在板内核群的其他部分以及丘脑腹侧、前侧、内侧、外侧和后侧核群的其他丘脑核中也发现了额外的标记细胞。标记细胞的分布因腹侧纹状体注射区域的不同而有所变化。腹侧纹状体的所有区域都接受来自中线丘脑核和束旁核的强烈投射。此外，腹侧纹状体的内侧区域接受来自中央上外侧核、腹前核大细胞亚群以及背内侧核部分区域的大量投射。将示踪剂注射到腹侧纹状体外侧区域后，在板内和丘脑腹侧核群的核中可见少数散在的标记神经元，在背内侧核中偶尔可见标记细胞。腹侧纹状体的中央区域，包括伏隔核核心的背侧部分，接受来自中线丘脑的有限投射，主要来自菱形核。它从中央内侧核以及丘脑腹侧、前侧和内侧核群接受的投射要少得多。伏隔核壳从丘脑接受的投射最为有限，几乎完全由中线丘脑核以及中央内侧核和束旁核支配。壳区与腹侧纹状体的其他部分的区别在于，它从丘脑腹侧、前侧、内侧和外侧核接受的投射最少。
