STUDY OF CNS NEUROPEPTIDES WITH PEPTIDE-TOXIN COMPLEXES

这个项目的目标是利用杂化分子 神经肽和白喉毒素或凝集素作为神经毒素或凝集素 药理拮抗剂用于研究神经肽受体 中枢神经系统(CNS)中的细胞，重点是基底细胞 神经节。促甲状腺激素释放激素、P物质和生长抑素 将会被研究。使用这些复合体的基本原理是 白喉毒素的无毒片段或特定的凝集素 通过将毒素与神经肽受体络合来承载神经肽受体的细胞 神经肽。这个项目试图确定在什么情况下 这种杂交体对基底神经节中的中枢神经系统神经元具有毒性 体内和体外的神经肽受体。使用定向的抗体 针对白喉毒素片段，该项目还将尝试 用免疫组织化学方法显示神经细胞上的神经肽受体。 以前的工作证明了TRH-白喉的受体特异性毒性 毒素杂交体体外抗大鼠垂体瘤细胞。这个项目将 脊髓TRH-毒素杂交体体内毒性条件的建立 脊髓和垂体，TRH纤维和受体存在的区域，通过 全身手术后的形态改变和受体可视化检查 或鞘内注射复合体。在确定了可行性之后 对于中枢神经系统神经元，神经肽P物质和 与毒素复合的生长抑素将被评估受体结合情况 原代培养的中脑、纹状体或 皮质神经元。P物质和生长抑素毒素的体内分析 复合体将在黑质纹状体系统由局部实施 脑内注射和黑质纹状体随后的变化 神经递质的代谢和行为依赖于 黑质纹状体系统。 这一工具可以提供一种更好地理解过程的方法 一些中枢神经系统神经元明显的选择性易损性 神经系统退行性疾病的过早死亡，尤其是 在基底节(例如：帕金森氏症、亨廷顿氏症、阿尔茨海默氏症)， 允许(1)神经肽的功能和药理分析 神经元，(2)神经肽受体在脑内的分布特征 死后组织，(3)对影响死亡的因素进行分析。 对多肽-毒素杂交物的退行性反应，以及(4)选择性 神经元丢失。

The goal of this project is to utilize hybrid molecules between neuropeptides and fragments of diptheria toxin or lectins as neurotoxins or pharmacological antagonists to investigate neuropeptide receptor-containing cells in the central nervous system (CNS) with emphasis on the basal ganglia. Thyrotropin releasing hormone (TRH), substance P and somatostatin will be studied. The rationale for the use of these complexes is to target an otherwise nontoxic fragment of diptheria toxin or a lectin to specific neuropeptide receptor-bearing cells by complexing a toxin to a neuropeptide. This project seeks to determine the conditions under which such hybrids are toxic to CNS neurons in the basal ganglia bearing specific neuropeptide receptors in vivo and in vitro. Using an antibody directed against the diptheria toxin fragment, this project will also attempt to visualize neuropeptide receptors on neurons by immunohistochemistry. Previous work demonstrated receptor-specific toxicity of the TRH-diptheria toxin hybrid in vitro against rat pituitary tumor cells. This project will establish conditions for in vivo toxicity of the TRH-toxin hybrid in spinal cord and pituitary, regions where TRH fibers and receptors are present, by examining morphological changes and receptor visualization after systemic or intrathecal delivery of the complex. Having established the feasibility of this methodology for CNS neurons, the neuropeptides substance P and somatostatin, complexed to toxins, will be evaluated for receptor binding and toxicity in vitro in primary cultures of mesencephalic, striatal or cortical neurons. In vivo analysis of substance P and somatostatin-toxin complexes will be performed in the nigrostriatal system by local intracerebral injections and subsequent changes in nigrostriatal neurotransmitter metabolism and behaviors dependent on the integrity of the nigrostriatal system. This tool may provide a means to a better understanding of the processes responsible for the apparent selective vulnerability of some CNS neurons to premature death in degenerative diseases of the nervous system, especially in the basal ganglia (e.g.: Parkinson's, Huntington's, Alzheimer's), by permitting (1) functional and pharmacological analysis of neuropeptide neurons, (2) characterization of distribution of neuropeptide receptors in postmortem tissue, (3) analysis of the factors which regulate the degenerative response to peptide-toxin hybrids, and (4) models of selective neuron loss.