Faculty of Health Sciences, School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa.
Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, District of Columbia.
J Comp Neurol. 2019 Jul 1;527(10):1633-1653. doi: 10.1002/cne.24545. Epub 2018 Oct 30.
We examined the number, distribution, and immunoreactivity of the infracortical white matter neuronal population, also termed white matter interstitial cells (WMICs), in the brain of a lesser ape, the lar gibbon. Staining for neuronal nuclear marker (NeuN) revealed WMICs throughout the infracortical white matter, these cells being most numerous and dense close to cortical layer VI, decreasing significantly in density with depth in the white matter. Stereological analysis of NeuN-immunopositive cells revealed a global estimate of 67.5 million WMICs within the infracortical white matter of the gibbon brain, indicating that the WMICs are a numerically significant population, ~2.5% of the total cortical gray matter neurons that would be estimated for a primate brain the mass of that of the lar gibbon. Immunostaining revealed subpopulations of WMICs containing neuronal nitric oxide synthase (nNOS, ~7 million in number, with both small and large soma volumes), calretinin (8.6 million in number, all of similar soma volume), very few WMICs containing parvalbumin, and no calbindin-immunopositive neurons. These nNOS, calretinin, and parvalbumin immunopositive WMICs, presumably all inhibitory neurons, represent ~23.1% of the total WMIC population. As the white matter is affected in many cognitive conditions, such as schizophrenia, autism and also in neurodegenerative diseases, understanding these neurons across species is important for the translation of findings of neural dysfunction in animal models to humans. Furthermore, studies of WMICs in species such as apes provide a crucial phylogenetic context for understanding the evolution of these cell types in the human brain.
我们研究了数量、分布和皮质下白质神经元群体（也称为白质间质细胞 [WMICs]）的免疫反应性，该群体存在于较小的猿类——黑冠长臂猿的大脑中。神经元核标志物（NeuN）染色显示 WMICs 存在于皮质下白质的整个区域，这些细胞在靠近皮质层 VI 的地方数量最多且密集，在白质中的密度随着深度的增加而显著降低。NeuN 免疫阳性细胞的体视学分析显示，黑冠长臂猿大脑皮质下白质中 WMICs 的全球估计值约为 6750 万，这表明 WMICs 是一个数量可观的群体，约占皮质灰质神经元总数的 2.5%，而皮质灰质神经元总数估计为黑冠长臂猿大脑质量的 2.5%。免疫染色显示 WMIC 存在亚群，包含神经元型一氧化氮合酶（nNOS，数量约为 700 万，具有小和大的胞体体积）、钙视网膜蛋白（数量约为 860 万，均具有相似的胞体体积）、数量很少的含有副甲状腺蛋白的 WMIC 和无钙结合蛋白免疫阳性神经元。这些 nNOS、钙视网膜蛋白和副甲状腺蛋白免疫阳性 WMIC，可能都是抑制性神经元，代表总 WMIC 群体的~23.1%。由于白质在许多认知疾病中受到影响，如精神分裂症、自闭症，也在神经退行性疾病中受到影响，因此，了解这些跨物种的神经元对于将动物模型中神经功能障碍的发现转化为人类具有重要意义。此外，在类人猿等物种中研究 WMIC 为理解这些细胞类型在人类大脑中的进化提供了至关重要的进化背景。
