PROTEIN PHOSPHORYLATION AND LTP IN AGED ANIMALS

老年动物的蛋白质磷酸化和 LTP

• 批准号: 6311454
• 负责人: MICHAEL D BROWNING
• 金额: $ 14.76万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-05-01 至 2001-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6311454
• 关键词: GABA receptor; NMDA receptors; RNA splicing; Xenopus oocyte; aging; antioxidants; calcium channel; dietary control; electrostimulus; enzyme activity; glutamate receptor; hippocampus; laboratory rat; long term potentiation; neural plasticity; nutrition related tag; phosphoproteins; protein kinase A; protein kinase C; receptor expression; synapsins; western blottings

Aged individuals and individuals suffering from Alzheimer's disease typically have significant cognitive impairment. Similarly aged animals are also known to have profound deficits in learning and memory. However, it is only recently that significant progress has been made in understanding the molecular and cellular substrates of cognitive functioning. Thus an understanding of the cellular and molecular bases of age related-learning deficits is just beginning to emerge. Long-term potentiation (LTP) is a form of synaptic plasticity that has been widely touted as a cellular building block of learning and memory. During the previous grant period the P.I. demonstrated clear deficits in LTP induction in the CA1 area of aged Fischer 344 rats. Molecular correlates of LTP were also a major focus of previous work. The P.I. has shown that LTP-inducing stimuli produce an increase in the phosphorylation of synapsin a synaptic vesicle-associated phosphoprotein and has also shown that aged animals have significant deficits in synapsin phosphorylation. Moreover, The P.I. and his colleagues have recently developed the immunological reagents required to study the NMDA and kainate/AMPA receptors. These receptors are thought to play critical role in LTP and they appear to be defective in old animals. in the current proposal previous work on age-related deficits in LTP mechanisms will be extended and new studies of NMDA and kainate/AMPA receptors are planned. Second, the P.I. proposes to test whether treatments (caloric restriction an antioxidant therapy) which have been reported to ameliorate cognitive and other deficits seen with age may limit or eliminate age-related deficits in specific LTP mechanisms. These studies will involve both cellular and molecular analyses. The specific foci will be in four areas. First, the P.I. will test the hypothesis that aged animals will exhibit deficits in LTP induction in the dentate and CA3 regions of the hippocampus. The P.I. will then test the hypothesis that antioxidant treatment and/or caloric restriction may ameliorate age related-deficits in LTP induction. Second, the P.I. proposes to test the hypothesis that aged animals have deficits in symapsin phosphorylation induced by electrophysiological stimulation. When deficits are found it is proposed that antioxidant treatment and/or caloric restriction be tested for their ability to ameliorate these deficits. The P.I. proposes to test the hypothesis that NMDA and/or kainate/AMPA receptor function, expression and/or phosphorylation are altered in aged animals. If age related deficits in either of these receptors is selected, the P.I. will test the hypothesis that caloric restriction and/or antioxidant treatment may ameliorate these deficits. In the final aim of this proposal, the P.I. will test the hypothesis that kinase activation following LTP induction may be deficient in old animals. In addition, the P.I. also proposed to collaborate with Projects 1, 2 and 4. Purified kinases and antibodies will be provided for collaborative studies of GABAA-R and Ca2+ channel function in collaborative experiments with Projects 1 and 2 respectively. Lastly, synapsin I expression will be assayed as a measure of transplant development in collaboration with Project #4.

老年人和患有阿尔茨海默病的人 通常有严重的认知障碍。 年龄相似的动物 众所周知，他们在学习和记忆方面也存在严重缺陷。 然而， 直到最近，这方面才取得了重大进展 了解认知的分子和细胞基础 发挥作用。 因此，了解细胞和分子基础 与年龄相关的学习缺陷才刚刚开始出现。 长期 增强（LTP）是突触可塑性的一种形式，已被广泛研究 被誉为学习和记忆的细胞组成部分。 期间 上一个资助期的 P.I.在 LTP 诱导方面表现出明显的缺陷 在老年 Fischer 344 大鼠的 CA1 区。 LTP 的分子相关性是 也是前期工作的重点。 P.I.研究表明，LTP 诱导 刺激导致突触蛋白磷酸化增加 囊泡相关磷蛋白，并且还表明老年动物具有 突触蛋白磷酸化的显着缺陷。 此外，P.I.和 他的同事最近开发出了所需的免疫试剂 研究 NMDA 和红藻氨酸/AMPA 受体。 这些受体被认为 在 LTP 中发挥关键作用，但它们似乎在旧有缺陷 动物。 在当前的提案中，先前关于年龄相关缺陷的工作 LTP机制将得到扩展，NMDA和红藻氨酸/AMPA的新研究 受体已计划。 其次，P.I.建议测试是否 治疗（热量限制和抗氧化疗法） 据报道可以改善随着年龄增长而出现的认知缺陷和其他缺陷，可能会限制 或消除特定 LTP 机制中与年龄相关的缺陷。 这些 研究将涉及细胞和分子分析。 具体的 重点将集中在四个领域。 首先，P.I.将检验以下假设 老年动物将表现出齿状和 CA3 中 LTP 诱导的缺陷 海马体区域。 P.I.然后将检验以下假设 抗氧化治疗和/或热量限制可能会延缓衰老 LTP诱导的相关缺陷。 其次，P.I.建议测试 假设老年动物的交联酶磷酸化存在缺陷 由电生理刺激诱发。 当发现不足时 建议测试抗氧化治疗和/或热量限制 表彰他们改善这些缺陷的能力。 P.I.建议测试 NMDA 和/或红藻氨酸/AMPA 受体功能、表达的假设 和/或磷酸化在老年动物中发生改变。 如果与年龄有关 选择这些受体中的任何一个的缺陷，P.I.将测试 假设热量限制和/或抗氧化治疗可能 改善这些缺陷。 在该提案的最终目标中，P.I. 将检验 LTP 诱导后激酶激活可能的假设 缺乏老年动物。 此外，P.I.还建议 与项目 1、2 和 4 合作。纯化的激酶和抗体将 提供GABAA-R和Ca2+通道功能的合作研究 分别与项目 1 和 2 进行合作实验。 最后， 突触蛋白 I 表达将作为移植的衡量标准进行测定 与项目#4 合作开发。