HYPOPHYSIOTROPIC NEURON DIFFERENTIATION--TARGET FEEDBACK

垂体神经元分化--目标反馈

• 批准号: 2431161
• 负责人: CAROL J PHELPS
• 金额: $ 19.82万
• 依托单位: TULANE UNIVERSITY OF LOUISIANA
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-12-01 至 1999-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2431161
• 关键词: apoptosis; developmental genetics; developmental neurobiology; dwarfism; gene expression; gene mutation; growth factor receptors; hormone receptor; hormone regulation /control mechanism; hypothalamic pituitary axis; hypothalamus; immunocytochemistry; in situ hybridization; insulinlike growth factor; laboratory mouse; median eminence; neuroanatomy; neurogenesis; neuropharmacology; neurotrophic factors; prolactin; protooncogene; receptor expression; somatotropin; transcription factor

The broad, long-term objective of the proposed research is to define how target hormonal signals from the anterior pituitary affect differentiation of hypothalamic neurons that regulate pituitary function. The studies are designed to elucidate the influence of growth hormone (GH) and prolactin (PRL) on survival and morphology, transcriptional activation, and restriction in gene expression in hypophysiotropic neurons. The health relatedness of the project is in understanding the mechanism by which target signals or intermediate neurotrophic factors affect programmed neuronal cell death, synaptic connectivity and transmitter expression, not only in development, but in genetic disease, following trauma, or in the process of aging. The studies will be conducted in an animal model, the dwarf mouse, that exhibits genetic deficiency of GH and PRL, providing for dirt assessment of the effect of absent target signals, and in which effects of hormone treatment will be physiological, but not complicated by the presence of endogenous hormone. The specific aims are to determine 1) whether hypophysiotropic neuron programmed cell death is exaggerated, or abnormal axon morphology occurs, in the absence of GH and PRL, 2) the sites and mechanisms of GH and PRL influence on hypophysiotropic neurons, and 3) whether the abnormalities in GH and PRL-regulating neurons arise from a genetic defect inherent in the hypothalamus, or occur in response to a primary pituitary mutation. The overall experimental design is comparison of untreated and hormone-treated dwarf and normal sibling mice, during postnatal development and as adults. The methods to be used for Specific Aim I are a) neuronal tract-tracing and b) identification (by immunocytochemistry; ICC) of protein markers of cell viability (metabolic enzyme) and cell death (immediate-early genes), in untreated developing mice and in mice treated with neurotrophic factors including GH and PRL. For Specific Aim 2, the method will be localization of PRL, GH and IGF-I receptors by ICC and in situ hybridization (ISHH) in hypothalamus and phenotypic identification of neurons which express c-fos in response to GH or PRL treatment. Specific Aim 3 will be addressed by examining expression (by ISHH) and structure (by restriction analysis and sequencing) of candidate genes for the Ames dwarf mutation, in a) hypothalamus and b) pituitary.

拟议的研究的广泛，长期目标是定义 垂体前靶向激素信号影响分化 调节垂体功能的下丘脑神经元。研究是 旨在阐明生长激素（GH）和催乳素的影响 （PRL）关于生存和形态，转录激活和 下生理神经元中基因表达的限制。健康 该项目的相关性在于理解该机制 目标信号或中间神经营养因素会影响编程 神经元细胞死亡，突触连通性和发射器表达，不是 仅在发育中，但在遗传疾病中，创伤后或 衰老过程。研究将在动物模型中进行 矮小的小鼠，表现出GH和PRL的遗传缺乏，提供 污垢评估缺乏目标信号的效果，其中 激素治疗的影响将是生理的，但并不复杂 内源激素的存在。具体目的是确定1） 是夸张的下生理神经元编程的细胞死亡，还是 异常轴突形态发生，在没有GH和PRL的情况下，2） GH和PRL的位点和机制对下生理神经元的影响， 3）GH和PRL调节神经元的异常是否出现 从下丘脑固有的遗传缺陷，或出现在响应中 进行原发性垂体突变。总体实验设计是 比较未处理和激素治疗的矮人和正常兄弟姐妹小鼠的比较， 在产后发展和成年人期间。用于用于的方法 特定目的I是a）神经元路追踪和b）识别（通过 免疫细胞化学；细胞活力的蛋白质标志物的ICC（代谢 酶）和细胞死亡（即时至上的基因），未经处理的发育 小鼠和用神经营养因素（包括GH和PRL）治疗的小鼠。 对于特定目标2，该方法将是PRL，GH和IGF-I的定位 ICC和原位杂交（ISHH）的受体在下丘脑和 对GH的响应表达C-FO的神经元的表型鉴定 或PRL治疗。特定目标3将通过检查表达来解决 （由ISHH）和结构（通过限制分析和测序） AMES矮人突变的候选基因，在A）下丘脑和B）中 垂体。