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目的探讨小鼠脊髓发育过程中血管-干细胞龛对神经干细胞分化、增殖和迁移的影响;探讨龛中的各种细胞、血管在发育中的变化及相互作用。方法发育过程中的胚胎鼠或生后小鼠150只,取脊髓腰膨大处的横断面切片。采用5-溴脱氧尿嘧啶核苷(BrdU)免疫荧光标记神经干细胞;用尼氏(Nissl)染色观察神经元的发育和形态变化;利用血管墨汁灌注结合免疫荧光三重标记的方法检测神经干细胞、神经元和神经胶质细胞在小鼠胚胎期及生后的形态分布变化;同时对脊髓内血管发育的动态变化进行形态学观察和体视学处理。结果妊娠14d(E14)小鼠脊髓内即有BrdU标记的阳性细胞,均匀分布。新生的神经元自神经管侧脑室下带迁移至中间层附近,逐渐分化为神经元,并集中于灰质呈现典型的“H”型。统计学分析表明,BrdU阳性细胞计数在发育中呈现抛物线,高峰值位于出生3d(P3)左右。此外,神经胶质细胞的祖细胞最早集中于边缘白质,随后又向中央的灰质回迁。血管发育经历了早期均匀分布,成年后集中在灰质分布的过程。血管、神经干细胞、神经元和神经胶质细胞构成了所谓的血管-干细胞龛。血管-干细胞龛主要位于侧脑室下带和灰质附近,其中的血管、神经干细胞、神经元和神经胶质细胞互相交织、紧密联系。结论血管-神经干细胞龛与脊髓发育紧密联系,同时影响神经元、神经胶质细胞和血管的相互作用。血管-神经干细胞龛为脊髓发育及神经元和神经胶质细胞分化提供了适宜的微环境。
Objective To investigate the effects of vascular-stem cell niche on the differentiation, proliferation and migration of neural stem cells in developing spinal cord of mice and to explore the changes and interactions of various cells and blood vessels in the niche. Methods 150 embryos or postnatal mice during the development of the method were taken from the lumbar enlargement of the spinal cord. The neural stem cells were labeled by BrdU immunofluorescence. The development and morphological changes of neurons were observed by Nissl staining. The proliferation of neural stem cells and nerves were detected by ink perfusion and triple immunofluorescence staining The morphological changes and morphological changes of glial cells were observed during the embryonic and postnatal periods of mice. At the same time, morphological and stereological changes of the dynamic changes of blood vessels in the spinal cord were observed. Results BrdU-labeled positive cells in the spinal cord of 14-day gestation (E14) mice were evenly distributed. Neonatal neurons migrate from the subventricular zone of the neural tube to the vicinity of the middle layer, gradually differentiate into neurons, and focus on the gray matter typical of “H” type. Statistical analysis showed that the number of BrdU positive cells showed a parabola during development, and the peak value was around 3d (P3) after birth. In addition, glial progenitor cells first focus on the edge of the white matter, and then move back to the central gray matter. Vascular development has experienced an early uniform distribution, concentrated in adult gray matter distribution process. Blood vessels, neural stem cells, neurons and glial cells make up the so-called vascular-stem cell niche. Vascular - stem cell niche is mainly located in the lateral ventricle and gray matter, including blood vessels, neural stem cells, neurons and glial cells intertwined closely. Conclusion The vascular niche of neural stem cells is closely related to the development of the spinal cord and affects the interaction between neurons, glia and blood vessels. The vascular-neural stem cell niche provides a suitable microenvironment for spinal cord development and neuronal and glial differentiation.