Laboratory of Experimental Ontogeny (LEO), Anatomy and Developmental Biology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.
J Comp Neurol. 2011 Dec 15;519(18):3727-47. doi: 10.1002/cne.22687.
The habenular complex (HbCpx) is a phylogenetically conserved brain structure located in the epithalamus of vertebrates. Despite its fundamental role in decision-making processes and the proposed link between habenular dysfunction and neuropsychiatric conditions, little is known about the structural and functional organization of the HbCpx in humans. The goal of this study was thus to provide a first systematic morphologic and immunohistochemical analysis of the human HbCpx to begin dissecting its nuclear and subnuclear organization. Our results confirmed that the human HbCpx is subdivided into medial (MHb) and lateral (LHb) nuclei, each showing a large degree of intranuclear morphologic heterogeneity. Analysis of serially stained sections using a combination of morphologic and immunohistochemical criteria allowed the distinction of five subnuclei in both the MHb and LHb. Overall, the observed subnuclear organization of the MHb in humans resembles the organization of subnuclei in the MHb of rats. The shape, relative size, and intranuclear organization of the LHb, however, show significant differences. The contribution of the LHb to the entire HbCpx is about five times larger in humans than in rats. Noteworthy, a dorsal domain of the LHb that contains afferent myelinated fibers from the stria medullaris and shows GABA-(B) -R(1) immunoreactive cells, appears substantially enlarged in humans when compared to rats. This feature seems to account for a large part of the relative growth in size of the LHb in humans and opens the intriguing possibility of an increased influence of limbic and striatal afferents into the LHb of humans.
缰核复合体（HbCpx）是位于脊椎动物上丘脑的一个进化保守的脑结构。尽管它在决策过程中起着重要作用，并且缰核功能障碍与神经精神疾病之间存在关联，但人们对人类缰核复合体的结构和功能组织知之甚少。因此，本研究的目的是首次对人类缰核复合体进行系统的形态学和免疫组织化学分析，以开始剖析其核和亚核组织。我们的研究结果证实，人类缰核复合体分为内侧（MHb）和外侧（LHb）核，每个核都表现出很大程度的核内形态异质性。使用形态学和免疫组织化学标准的组合对连续染色的切片进行分析，允许在 MHb 和 LHb 中区分五个亚核。总的来说，人类 MHb 的观察到的亚核组织类似于大鼠 MHb 的亚核组织。然而，LHb 的形状、相对大小和核内组织显示出显著差异。LHb 对整个缰核复合体的贡献在人类中约是大鼠的五倍。值得注意的是，LHb 的背侧区域包含来自髓纹的有髓传入纤维，并显示 GABA-(B)-R(1)免疫反应性细胞，与大鼠相比，人类的 LHb 明显增大。这个特征似乎解释了人类 LHb 相对大小增长的很大一部分，并为边缘和纹状体传入纤维对人类 LHb 的影响增加提供了有趣的可能性。
