PLASTICITY IN THE AGING OLFACTORY SYSTEM

老化嗅觉系统的可塑性

基本信息

批准号：
2732516
负责人：
Harriet D. Baker
金额：
$ 32.01万
依托单位：
WINIFRED MASTERSON BURKE MED RES INST
依托单位国家：
美国
项目类别：
财政年份：
1991
资助国家：
美国
起止时间：
1991-02-01 至 2001-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/2732516
关键词：
DNA footprinting aging enzyme induction /repression gel mobility shift assay genetically modified animals laboratory mouse neural plasticity olfactions olfactory lobe olfactory stimulus polymerase chain reaction sensory deprivation tissue /cell culture transcription factor tyrosine 3 monooxygenase

项目摘要

DESCRIPTION (Adapted from the Investigator's Abstract): The olfactory receptor epithelium displays regenerative capacity in adult animals, requiring continuous plasticity within its central nervous system target, the olfactory bulb. Tyrosine hydroxylase (TH), the rate limiting enzyme in catecholamine biosynthesis is found in dopaminergic (DA) periglomerular cells intrinsic to the olfactory bulb that regulate afferent stimulation of mitral cells. Throughout life, TH expression in the DA neurons exhibits profound regulation mediated by patterned olfactory stimulation (odorant stim.). The mechanisms regulating TH expression have yet to be analyzed in the olfactory bulb especially at the gene level. The investigators hypothesize that olfaction results in a cascade of events involving synthesis and/or phosphorylation of transcription factors that maintain TH gene expression. Four specific aims are proposed that will address the cisand transacting elements involved in TH gene regulation. Aim 1 will utilize gel mobility shift, RT-PCR and DNA footprinting techniques to identify the transcription factors specifically regulated in the mouse olfactory bulb. Differential display will be used to identify genes exhibiting altered regulation in parallel with TH. Aim 2 will use in vivo transgenic mouse techniques to identify upstream binding domains that are sufficient for both normal and regulated TH expression in the olfactory bulb. Aim 3 will use in vivo labeling techniques to localize altered expression of transcription factors in DA neurons in model systems exhibiting modified TH gene expression. Differentiated, odorant deprived young and aged animals as well as transgenic mice null for expression of olfactory marker protein will be used to investigate gene regulation in animals with altered TH expression. Aim 4 will employ immortalized and primary cell cultures derived from neonatal olfactory bulb to modify TH expression under controlled conditions and correlate those changes with expression of transcription factors. Collectively, these experiments will begin to define the molecular mechanisms regulating TH expression in the olfactory bulb. Because expression of TH is a definitive indicator of the integrity of olfactory afferent innervation, these findings will impact not only on understanding regulation of this enzyme, but generally on transsynaptic control of olfactory bulb function. The proposed studies will thus provide insight into the mechanisms underlying altered plasticity in the aging olfactory system. Hence, this research project addresses the etiology underlying compromised olfactory function observed during both normal aging and in degenerative disorders such as Alzheimer's and Parkinson's disease.

描述（改编自研究者摘要）：嗅觉受体上皮在成年动物中表现出再生能力，需要其中枢神经系统目标的持续可塑性，嗅球。酪氨酸羟化酶 (TH)，限速酶儿茶酚胺生物合成存在于多巴胺能 (DA) 肾小球周围嗅球固有的细胞，调节传入刺激二尖瓣细胞。在整个生命周期中，DA 神经元中的 TH 表达表现出由模式化嗅觉刺激介导的深刻调节（气味刺激。）。 TH表达的调节机制还有待分析嗅球，尤其是在基因水平上。调查人员假设嗅觉导致一系列事件，涉及维持 TH 的转录因子的合成和/或磷酸化基因表达。提出了四个具体目标来解决参与 TH 基因调控的顺式和反式元件。目标1将利用凝胶迁移率变化、RT-PCR 和 DNA 足迹技术鉴定小鼠中特异性调节的转录因子嗅球。差异显示将用于识别基因与 TH 并行地表现出调节改变。目标2将在vivo使用转基因小鼠技术来鉴定上游结合域足以满足嗅觉中正常和调节的 TH 表达电灯泡。目标 3 将使用体内标记技术来定位改变的模型系统中 DA 神经元转录因子的表达显示出改变的 TH 基因表达。差异化、无气味年轻和年老的动物以及转基因小鼠不表达嗅觉标记蛋白将用于研究基因调控 TH 表达改变的动物。目标 4 将雇佣不朽的和来自新生儿嗅球的原代细胞培养物可修饰 TH 在受控条件下表达并将这些变化与转录因子的表达。总的来说，这些实验将开始定义调节 TH 表达的分子机制嗅球。因为 TH 的表达是一个明确的指标嗅觉传入神经支配的完整性，这些发现不会影响仅了解这种酶的调节，但一般来说嗅球功能的跨突触控制。拟议的研究将从而深入了解可塑性改变背后的机制老化的嗅觉系统。因此，本研究项目旨在解决在这两种情况下观察到的嗅觉功能受损的病因学正常衰老和退行性疾病，如阿尔茨海默病和帕金森病。