W.M. Keck Laboratory for Biological Imaging, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
PLoS One. 2011 Apr 7;6(4):e18535. doi: 10.1371/journal.pone.0018535.
Neurons and glial cells in the developing brain arise from neural progenitor cells (NPCs). Nestin, an intermediate filament protein, is thought to be expressed exclusively by NPCs in the normal brain, and is replaced by the expression of proteins specific for neurons or glia in differentiated cells. Nestin expressing NPCs are found in the adult brain in the subventricular zone (SVZ) of the lateral ventricle and the subgranular zone (SGZ) of the dentate gyrus. While significant attention has been paid to studying NPCs in the SVZ and SGZ in the adult brain, relatively little attention has been paid to determining whether nestin-expressing neural cells (NECs) exist outside of the SVZ and SGZ. We therefore stained sections immunocytochemically from the adult rat and human brain for NECs, observed four distinct classes of these cells, and present here the first comprehensive report on these cells. Class I cells are among the smallest neural cells in the brain and are widely distributed. Class II cells are located in the walls of the aqueduct and third ventricle. Class IV cells are found throughout the forebrain and typically reside immediately adjacent to a neuron. Class III cells are observed only in the basal forebrain and closely related areas such as the hippocampus and corpus striatum. Class III cells resemble neurons structurally and co-express markers associated exclusively with neurons. Cell proliferation experiments demonstrate that Class III cells are not recently born. Instead, these cells appear to be mature neurons in the adult brain that express nestin. Neurons that express nestin are not supposed to exist in the brain at any stage of development. That these unique neurons are found only in brain regions involved in higher order cognitive function suggests that they may be remodeling their cytoskeleton in supporting the neural plasticity required for these functions.
发育中的大脑中的神经元和神经胶质细胞来源于神经祖细胞 (NPC)。巢蛋白是一种中间丝蛋白，被认为仅在正常大脑中的 NPC 中表达，并且在分化细胞中被特异性表达神经元或神经胶质的蛋白质所取代。在成年大脑的侧脑室室下区 (SVZ) 和齿状回颗粒下区 (SGZ) 中可以发现表达巢蛋白的 NPC。虽然人们对成年大脑中 SVZ 和 SGZ 中的 NPC 进行了大量研究，但对于确定 SVZ 和 SGZ 之外是否存在表达巢蛋白的神经细胞 (NEC) ，关注相对较少。因此，我们对成年大鼠和人大脑的切片进行了免疫细胞化学染色，以寻找 NEC，观察到这些细胞有四种不同的类型，并在此首次全面报告了这些细胞。I 型细胞是大脑中最小的神经细胞之一，分布广泛。II 型细胞位于导水管和第三脑室的壁上。IV 型细胞分布于前脑，通常紧邻神经元。III 型细胞仅在基底前脑和海马体和纹状体等密切相关的区域观察到。III 型细胞在结构上类似于神经元，并共同表达与神经元特异性相关的标志物。细胞增殖实验表明，III 型细胞不是最近才产生的。相反，这些细胞似乎是成年大脑中表达巢蛋白的成熟神经元。在发育的任何阶段，表达巢蛋白的神经元都不应该存在于大脑中。这些独特的神经元仅存在于与高级认知功能相关的脑区，这表明它们可能在重塑其细胞骨架，以支持这些功能所需的神经可塑性。
