Cellular Mechanisms of Learning and Memory in Drosophila

描述（由申请人提供）：本提案描述了新型试剂和技术的开发和优化，以测量和实验干扰果蝇中枢神经系统神经元树突的生长和活动依赖的可塑性，并研究其长期行为适应的结果。这些技术一方面有效地将行为分析与单个中枢神经系统神经元的可见荧光标记（如GFP）转基因标记、这些神经元中选择的蛋白质的伴随表达、神经元树突的共聚焦显微成像以及使用专用计算机算法对这些树突进行3D重建相结合。我们使用这套技术来测试myb相关转录因子Adf-1通过控制神经元树突的结构和功能特性来调节果蝇的学习和记忆的假设，这是CaMKII驱动的信号通路的下游，作为原理证明。Adf-1在果蝇神经系统中广泛表达，包括运动神经元和学习和记忆所需的高级大脑区域，类似于Myb在脊椎动物大脑中的表达。引人注目的是，据报道，Adf-1突变体（称为nalyot）在长期记忆形成方面也存在严重缺陷。迄今为止获得的结果表明，Adf-1强烈调节树突生长。基于这些观察，我们提出神经元Adf-1通过调节神经元树突的活动依赖性可塑性，指导控制长期行为适应（包括学习和记忆）的细胞机制。综上所述，这些研究不仅揭示了通过调节活动依赖性树突可塑性来控制学习和记忆的基本分子机制，而且为长期行为适应背景下树突结构和功能可塑性的测量奠定了坚实的技术基础。

DESCRIPTION (provided by applicant): This proposal describes the development and optimization of novel reagents and technologies to measure and experimentally perturb growth and activity-dependent plasticity of neuronal dendrites in Drosophila central nervous system neurons in vivo and examine their outcome on long-term behavioral adaptation. These techniques effectively combine behavioral analysis on one hand with transgenic labeling of individual central nervous system neurons with visible fluorescent markers (e.g. GFP), concomitant expression of proteins of choice in these neurons, confocal microscopic imaging of neuronal dendrites, and 3D reconstruction of these dendrites using dedicated computer algorithms on the other. We use this suite of techniques to test the hypothesis that the Myb-related transcription factor Adf-1 regulates learning and memory in Drosophila by controlling structural and functional properties of neuronal dendrites, downstream of a signaling pathway driven by CaMKII, as proof of principle. Adf-1 is expressed widely in the fly nervous system including motor neurons and higher brain regions required for learning and memory, similar to reported Myb expression in the vertebrate brain. Strikingly, mutants in Adf-1 (called nalyot) are also reported to have dramatic deficits in long-term memory formation. Results obtained thus far suggest Adf-1 strongly regulates dendrite growth. Based on these observations, we propose that neuronal Adf-1, by regulating activity- dependent plasticity of neuronal dendrites, instructs cellular mechanisms that control long-term behavioral adaptation (including learning and memory). Upon conclusion, these studies should not only reveal fundamental molecular mechanisms that, through regulation of activity-dependent dendritic plasticity, control learning and memory, but also firmly establish widely useful techniques to measure structural and functional plasticity of dendrites in the context of long-term behavioral adaptation. PUBLIC HEALTH RELEVANCE: The proposed project aims to develop novel genetic and imaging techniques to measure plasticity of neuronal dendrites in vivo and correlate them with behavioral changes. As proof of principle, we will use these techniques to study the role of a conserved transcription factor that controls long-term memory in Drosophila, in the regulation of dendritic architecture and long-term adaptive behavior. Upon conclusion these studies will illuminate fundamental cellular mechanisms by which gene expression programs regulate behavior and establish multiple useful technologies for future experiments.