DEVELOPMENT OF NEURONS IN THE GUT

肠道需要内部神经元的存在才能进行运动 并发生吸收/分泌。内源性神经元或肠道神经元 从离开神经管进入神经管的神经脊细胞发育而来 直觉。在肠道内，这些脊细胞迁移、聚集、增殖、 并分化成神经元，形成调节 肠道动力。这项研究的长期目标是阐明 调节肠道神经系统形成的机制。 神经脊细胞沿肠道的位置对 随后的神经元发育和肠道运动。波峰失效 细胞占据肠道区域会导致运动障碍。先天 巨结肠(先天性巨结肠症)是由于缺乏波峰所致 末端肠道中的细胞和假性梗阻可能是由于 中肠或后肠中边缘的或数量不足的脊细胞。 脊细胞从神经轴的两个层面进入肠道：后脑。 (迷走神经脊)和骶神经管(骶神经脊)。 迷走神经脊细胞进入前部并向尾部迁移到 后肠，而骶骨脊细胞进入后肠并移动 吻部到中肠。 脊状细胞沿肠道的分布取决于许多 各种因素。这项提案的目标是评估这些因素 系统地：脊细胞从哪里来，从哪里进入 肠道，它们在肠道中的去向，以及它们在肠道中形成的东西。波峰 细胞将通过注射复制不能复制的逆转录病毒来标记 携带Lac Z基因，并将进行组织化学检测。 逆转录病毒注射结合神经组织免疫染色 标记物将被用来确定骶骨顶对 后肠的肠道神经系统。流浪汉的贡献 后肠的隆起将通过手术切除骶骨来确定 克雷斯特。为了深入了解细胞迁移的控制， 迷走神经脊细胞沿肠道的分布将用 考虑到它们起源于神经轴。减少经济衰退的影响 进入肠道的迷走神经峰数将通过消融来评估 迷走神经脊的一部分，并确定肠道的长度 神经紧张。迷走神经在迷走神经移行中的作用 波峰将通过消融迷走神经来确定。了解以下内容 在迁移的过程中，活的脊细胞的运动行为会 当它们在肠道中就地移动时被描述为特征。这件事会做到的 通过用荧光亲脂活性染料DII标记细胞，以及 用荧光显微镜和灵敏的方法跟踪它们的运动 摄影机。

The gut requires the presence of intrinsic neurons in order for motility and absorption/secretion to occur. The intrinsic or enteric neurons develop from neural crest cells that leave the neural tube and enter the gut. Within the gut these crest cells migrate, aggregate, proliferate, and differentiate into neurons which form the circuitry that regulates gut motility. The long-term objective of this study is to elucidate the mechanisms which regulate the formation of the enteric nervous system. The placement of the neural crest cells along the gut is critical to the subsequent development of neurons and gut motility. Failure of crest cells to occupy regions of gut results in motility disorders. Congenital megacolon (Hirschsprung's disease) results from the absence of crest cells in the terminal bowel and pseudoobstruction may result from a marginal or inadequate number of crest cells in the midgut or hindgut. Crest cells enter the gut from two levels of the neuroaxis: the hindbrain (vagal neural crest) and the sacral neural tube (sacral neural crest). Vagal neural crest cells enter the foregut and migrate caudally to the hindgut, while the sacral crest cells enter the hindgut and move rostrally to the midgut. The disposition of the crest cells along the gut depends on a number of factors. The objectives of this proposal are to evaluate these factors systematically: where the crest cells come from, where they enter the gut, where they go in the gut, and what they form in the gut. Crest cells will be marked by injection of a replication-incompetent retrovirus which carries the Lac Z gene and will be detected histochemically. Injection of retrovirus in combination with immunostaining for neural markers will be used to establish the contribution of the sacral crest to the enteric nervous system in the hindgut. The contribution of the vagal crest to the hindgut will be determined by surgically ablating the sacral crest. To gain insight into the control of cell migration, the distribution of vagal crest cells along the gut will be mapped with respect to their origin in the neuroaxis. The effect of reducing the number of vagal crest entering the gut will be evaluated by ablating portions of the vagal crest, and determining the length of gut innervated. The role of the vagus nerve in the immigration of vagal crest will be determined by ablation of the vagus nerve. To learn about the process of migration, the motile behavior of living crest cells will be characterized as they move in situ through the gut. This will be done by labeling cells with the fluorescent lipophilic vital dye DiI, and following their movements with a fluorescent microscope and sensitive camera.