Shh及其受体Ptc和Smo在胚胎期小鼠5-HT能尾端缝核核团及缝核脊髓束表达特点的研究

发布时间：2018-11-10 17:25

【摘要】： 中枢神经系统有许多能传导特定信息的神经通路,这些神经通路通过轴突传导某种特定信息,如运动、视、听或感觉信息等。按神经信息的传导方向,神经通路可分为上行和下行两种。下行神经通路主要是由脑中的神经核团发出轴突并向脊髓尾端方向投射。缝核脊髓束(Raphespinal Tract, RST)是一条重要的下行神经通路,它由脑干的尾端缝核核团(Caudal Raphe Nuclei, CRN)发出并向脊髓尾端投射。因这些核团分泌5-羟色胺(5-HT)神经递质,故又称5-HT能神经元。我们以前的研究发现,5-HT能神经轴突在小鼠E11.5天时从CRN发出,E12.5-E16.5天,RST沿脊髓腹外侧投射至脊髓最尾端。Sonic hedgehog (Shh)是一种形成素,广泛参与胚胎期多种神经元的发育,主要表达在脊髓的底板,并可分泌到整个腹侧脊髓,调控脊髓腹侧神经元的发育。近年的研究表明,Shh也是一种神经轴突导向分子,控制一些神经轴突在发育期间的定向投射。本研究中,我们运用分子原位杂交技术,发现Shh mRNA表达在E12.5-E14.5天小鼠脊髓腹侧底板,并随着RST向尾端的投射而呈现出从头端到尾端梯度递减的表达特点。免疫组织化学法发现,Shh的受体Patched (Ptc)和Smoothened (Smo)也随着RST的投射而呈现出同的表达特点。E11.5天,Ptc在5-HT能CRN表达,但Smo却几乎不表达。E12.5-E14.5天,Ptc和Smo在5-HT能CRN及RST均有表达。我们的研究结果提示,Shh作为神经轴突导向分子,很有可能参与调控了5-HT能RST在脊髓中从头端向尾端的定向投射。
[Abstract]:The central nervous system has many neural pathways that transmit specific information, such as motor, visual, auditory or sensory information, through axons. According to the direction of nerve information transmission, neural pathways can be divided into uplink and downlink. The descending nerve pathway is mainly caused by axons from the nucleus of the brain and projected to the caudal end of the spinal cord. The spinal tract of raphe nucleus (Raphespinal Tract, RST) is an important descending nerve pathway. It is emitted by the (Caudal Raphe Nuclei, CRN) of the nucleus raphe nucleus caudalis in the brain stem and projected to the caudal end of the spinal cord. Because these nuclei secrete 5-hydroxytryptamine (5-HT) neurotransmitters, they are also called 5-HT neurons. Our previous studies have found that 5-HT can produce axons from CRN at E11.5 days in mice, and on E12.5-E16.5 days, RST projects to the caudal end of the spinal cord along the ventrolateral side of the spinal cord as a formin. It is widely involved in the development of various neurons in embryonic stage, mainly expressed in the spinal cord floor, and can be secreted to the whole ventral spinal cord, regulating the development of the ventral spinal cord neurons. Recent studies have shown that Shh is also a neuronal guidance molecule that controls the directional projection of some axons during development. In this study, we found that Shh mRNA was expressed in the ventral floor of the spinal cord of E12.5-E14.5 day mice by in situ hybridization, and showed a decreasing gradient from head to tail with the projection of RST to the tail. Immunohistochemical method showed that Patched (Ptc) and Smoothened (Smo), the receptors of Shh, also showed the same expression characteristics with the projection of RST. On E11.5 day, Ptc could express CRN in 5-HT, but Smo was hardly expressed on E12.5-E14.5 day. Both Ptc and Smo were expressed in 5-HT can CRN and RST. Our results suggest that Shh, as an axon oriented molecule, may be involved in the regulation of 5-HT directed projection of RST from the head to the tail of the spinal cord.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2010
【分类号】：R346

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