DEVELOPMENT OF SYNAPSES BETWEEN IDENTIFIED NEURONS

神经系统组织的本质是建立 突触回路。要求非常高的精确度。 这些回路的构造，以及许多行为障碍 发生在人类和其他动物身上的是由于大脑中 突触连接的发育。这个项目的长期目标是 研究是为了阐明基本的细胞和分子机制 形成和维持特定的突触连接， 以蟑螂的末梢神经节为模型系统。许多. 控制神经元发育的其他方面的机制有 在整个进化过程中都是守恒的，这使得它有可能 这项工作将有助于我们最终了解我们的 自己的大脑是组装起来的。这个项目的第一个具体目标是 确定突触形成的序列和特异性 利用细胞内鉴定胚胎发育过程中的神经元 记录、染料注射以及光学和电子显微镜检查。第二 目的是评估宫颈传入神经再生的准确性。 它们的树枝和突触连接，使用组合 细胞内记录、染料注射和形态计量分析。这个 第三个具体目标是确定生理和解剖学基础 在突变蟑螂中存在突触竞争 突触前神经元，使用量子分析和 定量电子显微镜。细胞内染料注射将是 用来找出多余的轴突是否在 终末神经节多于正常轴突。同步的效果 将研究再生对相对突触效率的影响。 将使用细胞内记录和染料注射来追踪 本项目的第四个目标；确定竞争对手的角色 遗传野生型胚胎后发育过程中的相互作用 动物。

The essence of nervous system organization is the establishment of synaptic circuits. A great deal of precision is demanded in the construction of these circuits, and many of the disorders of behaviour that occur in humans and other animals are due to abnormalities in the development of synaptic connections. The long-term objectives of this research are to elucidate basic cellular and molecular mechanisms which underlie the formation and maintenance of specific synaptic connections, using the terminal ganglion of the cockroach as a model system. Many of the mechanisms which control other aspects of neuronal development have been shown to be conserved throughout evolution, which makes it likely that this work will contribute to our eventual understanding of how our own brains are assembled. The first specific aim of this project is to determine the sequence and specificity of synapse formation between identified neurons during embryonic development, using intracellular recording, dye injection and light and electron microscopy. The second aim is to assess the accuracy with which cercal afferents regenerate their arborization and synaptic connections, using a combination of intracellular recording, dye injection, and morphometric analysis. The third specific aim is to determine the physiological and anatomical basis for synaptic competition in mutant cockroaches with a supernumerary presynaptic neuron, using a combination of quantal analysis and quantitative electron microscopy. Intracellular dye injection will be used to find out whether the supernumerary axon arrives later in the terminal ganglion than the normal axons. The effect of synchronized regeneration on the relative synaptic efficacies will be investigated. Intracellular recording and dye injection will be used to pursue the fourth aim of this project; to determine the role of competitive interactions during postembryonic development of genetically wild-type animals.