FORMATION & ELIMINATION OF SYNAPSES

长期目标是阐明细胞和分子 突触的发育、维持和可塑性机制。 最近的研究表明，花生凝集素（PNA）识别 细胞外基质中的突触特异性分子， 荧光缀合物染色活青蛙神经肌肉接头。 该建议旨在进一步表征PNA结合， 研究PNA结合分子（PNA-BM）的可能作用 青蛙终板。 (1)将使用金结合物PNA进行着床后染色 检查PNA-BM的超微结构定位， 神经肌肉接头 (2)唾液酸去除的影响 神经氨酸酶对PNA结合的影响将在正常和 发展中的连接。 (3)PNA-BM分布的变化 与神经支配有关，将用电子 整个封片的显微镜和落射荧光显微镜 以及去神经支配的，神经支配的， 神经肌肉接头 (4)PNA将应用于成人肌肉 在PNA-BM和乙酰胆碱受体的神经再支配过程中， 文化也将受到考验。 (5)神经末梢和突触 4-di-2-Asp和罗丹明染色的正常连接中的基质， PNA将通过视频增强在原位反复检查 显微镜 突触形成过程中突触基质的动态变化 形成和消除也将在现场进行检查。 （六） 正常、退化和 通过凝胶电泳检查发育终板， 用过氧化物酶缀合的PNA探测生物化学 PNA-BM的表征。 这项研究将表征一种新的分子探针， 神经肌肉接头，并提供进一步的见解，细胞 以及发育、维持和可塑性的分子机制 神经突触 阐明这些基本机制将有助于 对某些发展和 神经肌肉疾病

The long-term objectives are to elucidate cellular and molecular mechanisms of development, maintenance, and plasticity of synapses. Recent studies have shown that peanut agglutinin (PNA) recognizes synapse-specific molecules in the extracellular matrix, and its fluorescent conjugates stains living frog neuromuscular junctions. This proposal aims to characterize further the PNA-binding and to investigate the possible roles of PNA-binding molecules (PNA-BM) in frog endplates. (1) Postembedding staining with gold-conjugates PNA will be used to examine the ultrastructural localization of PNA-BM in neuromuscular junctions. (2) The effects of sialic acid removal by neuraminidase on PNA binding will be examined in normal and developing junctions. (3) Changes in the distribution of PNA-BM in relation to innervation will be examined with electron microscopy and epi-fluorescence light microscopy of whole mounts and cryosections of denervated, reinnervated, and developing neuromuscular junctions. (4) PNA will be applied to adult muscles during reinnervation of PNA-BM and acetylcholine receptors in culture also will be examined. (5) Nerve terminals and synaptic matrix in normal junctions stained with 4-di-2-Asp and rhodamine- PNA will be examined in situ repeatedly with video-enhanced microscopy. Dynamics changes in synaptic matrix during synapse formation and elimination will also be examined in situ. (6) Synaptic extracellular matrix of normal, degenerating, and developing endplates will be examined by gel electrophoresis and probed with peroxidase-conjugated PNA for biochemical characterization of PNA-BM. This research will characterize a new molecular probe for living neuromuscular junctions and provide further insights into cellular and molecular mechanisms of development, maintenance and plasticity of synapses. Elucidation of these basic mechanisms will enhance fundamental understanding of certain developmental and neuromuscular disorders.