Functional Anatomy of Learning and Memory in Drosophila

描述(申请人提供)：行为层面的研究表明，在脊椎动物和无脊椎动物物种中，记忆巩固涉及通过几个不同的时间“阶段”处理信息。在解剖学层面上，记忆似乎在许多情况下在不同的位置之间动态转移。即使在相对简单的无脊椎动物大脑中，联想学习的基本形式也可以依赖于相对较大的神经元网络中的多种机制。这一建议的核心是在果蝇中获得Gal4反应温度敏感(和显性负)的动力蛋白转基因(UAS-SHI/TS)，它允许温度依赖性和可逆性破坏神经功能。这种遗传工具提供了一个独特的机会，可以从功能上映射神经回路和复杂行为(如记忆)之间的关系。我们已经使用这种方法扰乱了苍蝇大脑几个不同亚区的神经元功能，从而剖析了获取和提取以及存储麻醉敏感和麻醉抵抗记忆的解剖学要求。这项提议的目标是进一步定义记忆形成、存储和检索的基本功能电路。 这项建议的三个具体目标是： 1-“功能解剖”--这11个非蘑菇体Gal4增强子系中的每一个，以及DPM和MB系，将被用于驱动Gal4反应的UAS-SHITS转基因的空间受限表达。然后，在记忆巩固的每个时间阶段，温度变化实验将被用来暂时扰乱这些病灶的神经元功能。 2-“记忆阶段的解剖学解剖”--在AIM#1中确定的功能相关的Gal4系将与“特定阶段”健忘症和萝卜突变体相结合。这种“双突变”方法将允许从萝卜依赖(麻醉抵抗)记忆中解剖失忆依赖记忆的解剖学要求，这种记忆是麻醉敏感的。 3-高分辨率成像-共聚焦成像将用于构建GFP报告表达的高分辨率解剖图谱，每个Gal4转座子系被确定为在特定目标I和2中功能相关。 我们将利用只有苍蝇才有的规模经济和分子遗传学工具来研究神经活动的时间和空间模式与大脑中正在进行的记忆巩固之间的关系。虽然神经系统的解剖线路图看起来是物种特有的，但这些回路中潜在的记忆的分子机制和行为特性是非常保守的。因此，对信息在相对简单的神经系统中如何处理的“逻辑”的理解可以极大地促进未来对人类认知的研究。

DESCRIPTION (provided by applicant): Studies at the behavioral level reveal that in both vertebrate and invertebrate species, memory consolidation involves processing of information through several distinct temporal "phases". At the anatomical level, memories appear in many cases to be dynamically transferred between distinct loci. Even elemental forms of associative learning in relatively simple invertebrate brains can rely on multiple mechanisms in relatively large networks of neurons. Central to this proposal is the availability in flies of a Gal4-responsive temperature-sensitive (and dominant negative) dynamin transgene (UAS-Shi/ ts), which permits temperature dependent and reversible disruption of neuronal function. This genetic tool provides a unique opportunity to functionally map the relationships between neural circuitry and a complex behavior such as memory. We already have used this method to disrupt neuronal function in several distinct sub-regions of the fly brain, thereby dissecting the anatomical requirements for acquisition versus retrieval as well as for storage of anesthesia-sensitive versus anesthesia-resistant memory. The goal of this proposal is to further define the functional circuitry underlying memory formation, storage and retrieval. The three Specific Aims of this proposal are: 1- "Functional anatomy"- Each of these 11 non-mushroom body Gal4 enhancer lines, as well as the DPM and MB lines, will be used to drive spatially restricted expression of the Gal4-responsive UAS-Shits transgene. Temperature-shift experiments then will be used to transiently disrupt neuronal function in these foci during each temporal phase of memory consolidation. 2- "Anatomical Dissection of Memory Phases" - Functionally relevant Gal4 lines identified in Aim #1 will be combined with the "phase specific" amnesiac and radish mutants. This "double mutant" approach will permit dissection of the anatomical requirements for amnesiac-dependent memory, which is anesthesia sensitive, from radish-dependant (anesthesia resistant) memory. 3- High Resolution Imaging- Confocal imaging will be used to construct a high-resolution anatomical map of GFP reporter expression for each Gal4 transposon line identified as functionally relevant in Specific Aims I and 2. We will take advantage of the economy-of-scale and molecular genetic tools available only in flies to investigate the relationships between temporal and spatial patterns of neural activity and the ongoing consolidation of memories in the brain. While the anatomical wiring diagram of nervous systems appear species specific, the molecular mechanisms and behavioral properties underlying memory within these circuits are remarkably conserved. As a result, an understanding of the "logic" of how information is processed in relatively simple nervous systems can greatly inform future investigations of human cognition.