CYCLIC-AMP MEDIATED GENE EXPRESSION IN APLYSIA MEMORY

海兔记忆中环腺苷酸介导的基因表达

• 批准号: 2249032
• 负责人: PRAMOD K DASH
• 金额: $ 17.14万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 1997-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2249032
• 关键词: Aplysia; cyclic AMP; gene expression; long term memory; microinjections; molecular cloning; molecular psychobiology; neural facilitation; regulatory gene; tissue /cell culture; transcription factor

When organisms learn, their memory can last either for a short or long- period of time. Studies show that short-term memory (lasting minutes to hours) involves covalent modifications of pre-existing proteins. In contrast, long-term memory (lasting hours to days) appears to involve new protein synthesis and gene expression. Inhibition of translation and transcription during the acquisition phase blocks the formation of long- term memory without any effect on short-term memory. Moreover, long-term memory is often accompanied and perhaps mediated by morphological changes in neurons. The biochemical events leading to long-term memory and the associated morphological changes are virtually unknown. While a few genes and proteins have been shown to be altered in their expression following long-term training, it has been difficult to investigate causal relationships between long-term memory formation and the functions of these identified genes and proteins. The purpose of this project is to identify and characterize transcription factors and immediate-early genes activated by long-term training and to investigate their functional role in memory formation and the associated morphological changes. We will carry out these experiments in the marine mollusc Aplysia californica. Because of its simple and accessible nervous system, Aplysia has been one of the major systems used in memory research. A critical locus for the storage of memory for long-term sensitization of the gill- and siphon- withdrawal reflex is the connection between the sensory neurons and the motor neurons which can be reconstituted in dissociated cell cultures. Previous studies in intact animals and in sensory-motor neuron cultures indicate that cAMP mediated gene induction may be necessary for long-term memory formation as well as the associated morphological changes in Aplysia. The project has four specific aims. Aim 1 is to test the hypothesis that the transcription factor CREB (cAMP responsive element binding protein) is part of the biochemical pathway by which long-term memory is induced in Aplysia. Aim 2 is to test the hypothesis that immediate-early genes are involved in the induction of long-term memory. Aim 3 is to test the hypothesis that morphological changes seen following long-term training are caused by activation of CREB protein. Aim 4 is to isolate the cDNA clone encoding Aplysia CREB protein and to test the hypothesis that microinjection of the Aplysia protein into sensory neurons can induce long-term facilitation and the associated morphological changes. A combination of biochemical, electrophysiological and behavioral experiments in intact animals, in semi-intact ganglia and in sensory-motor neuron cultures will be to test the above hypotheses. Understanding the biochemical pathway(s) involved in the formation of memory will provide insights into mechanisms responsible for establishment of long-lasting plasticities in the brain. This information also would be of great value in understanding the consequences of some morphological diseases associated with memory deficits as well as injury to the brain.

当生物体学习时，它们的记忆可以持续很短或很长时间- 段时间 研究表明，短期记忆（持续几分钟到 小时）涉及预先存在的蛋白质的共价修饰。在 相比之下，长期记忆（持续数小时至数天）似乎涉及新的 蛋白质合成和基因表达。 禁止翻译和 在获得阶段的转录阻断了长- 对短期记忆没有任何影响。此外，长期 记忆常常伴随着形态学的变化， 在神经元中。导致长期记忆的生化事件和 相关的形态学变化实际上是未知的。虽然一些基因 并且蛋白质的表达已经被证明在 长期训练，一直难以调查因果关系 长时记忆形成与脑功能的关系 这些被鉴定的基因和蛋白质。该项目的目的是 鉴定和表征转录因子和即刻早期基因 通过长期训练激活，并调查其功能作用 以及相关的形态学变化。我们将 在海洋软体动物加州滨螺中进行这些实验。 由于其简单易行的神经系统， 记忆研究的主要系统。一个关键的轨迹， 储存记忆，用于长期敏化鳃和虹吸管， 退缩反射是感觉神经元和神经元之间的联系。 运动神经元可以在分离的细胞培养物中重建。 先前在完整动物和感觉运动神经元培养中的研究 表明cAMP介导基因诱导可能是长期 记忆的形成以及相关的形态学变化， 阿托西亚。该项目有四个具体目标。目标1是测试 转录因子CREB（cAMP反应元件） 结合蛋白）是生化途径的一部分， 记忆是由失忆症引起的。目标2是检验以下假设 即刻早期基因参与长期记忆的诱导。 目的3是检验以下假设： 长期训练是由CREB蛋白激活引起的。目标4： 分离编码Aesthesia CREB蛋白的cDNA克隆， 感觉神经元内微量注射失神经蛋白假说 可以诱导长期的易化和相关的形态学 变化生物化学、电生理学和行为学的结合 在完整动物、半完整神经节和感觉运动神经节中的实验 神经元培养将用于测试上述假设。了解 参与记忆形成的生化途径将提供 深入了解负责建立持久和平与安全的机制， 大脑的可塑性这些信息也将是非常有价值的 在理解某些形态学疾病的后果时， 与记忆缺陷和大脑损伤有关。