SYNAPTIC INTEGRATION AND DEVELOPMENT IN COMMAND NEURONS

命令神经元的突触整合和发育

• 批准号: 3412319
• 负责人: DONALD Hine EDWARDS
• 金额: $ 12.58万
• 依托单位: GEORGIA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1996-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3412319
• 关键词: Malacostraca; animal developmental psychology; axon; biological models; biophysics; dendrites; electrical potential; electrophysiology; fresh water environment; ganglions; immature animal; interneurons; mature animal; mechanoreceptors; membrane structure; neuroanatomy; neurogenesis; neurons; stimulus /response; synapses

This research will investigate the effects of postembryonic growth on the ability of neurons to integrate and respond to synaptic inputs. During postembryonic development, most neurons elaborate new dendritic and axonal branches and increase the size of the soma, the lengths and diameters of the dendrites, and the length and diameter of the axon. Increases in neuronal size should decrease the input resistance and increase the input capacitance throughout the cell, and also increase the electrotonic separation of its different parts. These changes will alter the integrative and response characteristics of a neuron unless compensatory changes occur in the number and strength of inputs, in their spatial and temporal distribution, and in the nature and distribution of the cell's active and passive membrane. This project will examine this issue as it affects the lateral giant (LG) interneuron of crayfish during postembryonic growth of the animal from a 1 cm juvenile to a 10 cm adult. LG is a "command neuron" for the tailflip escape behavior, and is part of what is arguably the best-understood of all neural circuits. We propose to trace the growth of LG and its mechanosensory inputs to examine the suggestion that neuronal growth itself is responsible for the decline in LG's responsiveness to phasic mechanosensory stimuli, despite great increases in the number of afferent inputs the cell receives. We will determine how afferent synaptic terminals change during growth, and whether these changes succeed or fail to compensate for the growth of the postsynaptic cell. Finally, we will examine the hypothesis that the growth of the LG's electrotonic structure "tunes" the cell to respond to tactile stimuli of a size that matches the growing tailfan.

本研究将探讨胚后生长对胚胎发育的影响。 神经元整合和响应突触输入的能力。 期间 胚后发育，大多数神经元精心制作新的树突状细胞， 轴突分支增加，索马的大小、长度和 树突的直径以及轴突的长度和直径。 神经元大小的增加会降低输入电阻， 增加整个电池的输入电容，也增加 不同部位的电紧张性分离。 这些变化将改变 神经元的整合和反应特性，除非 补偿性变化发生在输入的数量和强度上， 空间和时间分布，并在性质和分布 细胞的主动膜和被动膜。 本项目将研究这个问题，因为它影响了横向巨人（LG） 螯虾胚后发育过程中中间神经元的变化 1厘米的少年到10厘米的成年人。 LG是一个“命令神经元”， 尾空翻逃脱行为，是什么可以说是一部分， 最容易理解的神经回路 我们打算追踪 LG及其机械感觉输入，以检查的建议， 神经元生长本身是导致LG的下降的原因。 对阶段性机械感觉刺激的反应，尽管有很大的增加， 细胞接受的传入输入的数量。 我们将确定 传入突触末梢在生长过程中是如何变化的， 改变成功或失败，以补偿突触后神经元的生长， cell. 最后，我们将检验一个假设，即 LG的电紧张结构“调谐”细胞以响应触觉 刺激的大小匹配不断增长的尾翼。