Project 1 Genetic Analysis of Cortical Behavioral Plasticity

尽管在过去的十年里，在分子、细胞和系统方面取得了重大进展 调节情景恐惧条件反射早期阶段的机制，一种情绪记忆模型， 这一过程的后期阶段仍然知之甚少。最近，我们实验室报告了基因、成像 和可逆的损害证据，支持长期记忆对背景条件作用的观点 取决于皮质区域，如前扣带回。现在，我们建议结合使用 遗传学、转基因、电生理学和双光子活体成像解开分子和细胞 构成远程情绪记忆基础的皮质可塑性机制。项目1的具体目标是： 1-识别远程记忆特定需要的基因，以进行情境条件反射。在我们的反面 正向遗传(RFG)试点筛选，随机选择55个转基因和KO 来自杰克逊实验室收集的生成器，我们发现2特别影响7天记忆(远程) 在不破坏1天记忆(近期)、一般活动水平或电击的情况下，进行情景条件反射 反应性。我们现在建议扩展这一屏幕，并在另外350个实验中测试情景恐惧条件反射 转基因和KO突变体。然后将对这些突变体进行躯体感觉(项目2)和视觉筛选 (项目3)可塑性缺陷，作为机械研究的前言(见下文)，以解开分子和 皮质和行为可塑性后期的生理机制。 2-推导出影响对语境的长期记忆的基因的区域和时间特异性突变 条件反射。我们建议使用loxP/Cre重组酶系统来控制细胞类型、脑区域 以及在AIM 1中分离到的突变的时间表达。 此外，还将在项目2和3中进行研究。 3-揭示脊椎前部翻转和稳定的皮质分子机制 扣带状。可塑性，包括行为可塑性(即远程记忆)，被认为涉及到 巩固和稳定存储信息所需的神经元结构。我们建议使用双光子 扫描共聚焦体内成像以检查影响远程记忆的突变是否也影响 大鼠远距离记忆所需皮质区域(即前扣带回)的脊柱翻转和稳定性 受过训练的和未受过训练的(上下文条件作用)突变体和对照。这些研究将平行相关 在项目2和3中进行了成像研究。 总之，这里描述的研究以及项目2和3中的相关研究将揭开基本的 大脑皮层如何编码和存储信息的分子、细胞和结构机制。这些 研究结果将对我们如何研究和治疗与情绪记忆相关的障碍产生关键影响。

Although in the last ten years there have been significant inroads into the molecular, cellular and systems mechanisms that mediate the early stages of contextual fear conditioning, a model of emotional memory, later stages of this process remain poorly understood. Recently our laboratory reported genetic, imaging and reversible lesion evidence that supports the idea that long-term memory for contextual conditioning depends on cortical regions, such as the anterior cingulate. Now, we propose to use a combination of genetics, transgenics, electrophysiology and 2-photon in vivo imaging to unravel the molecular and cellular mechanisms of cortical plasticity that underlie remote emotional memory. The specific aims of Project 1 are: 1- To identify genes specifically required for remote memory for contextual conditioning. In our Reverse Forward Genetic (RFG) pilot screen, out of 55 transgenics and KOs selected with a random number generator from the Jackson Laboratory collection, we found that 2 affect specifically 7-day memory (remote) for contextual conditioning, without disrupting 1-day memory (recent), general activity levels or shock reactivity. We now propose to extend this screen and test contextual fear conditioning in another 350 transgenic and KO mutants. These mutants will then be screened for somatosensory (Project 2) and visual (Project 3) plasticity deficits, as a preamble for mechanistic studies (see below) to unravel the molecular and physiological mechanisms underlying the later stages of cortical and behavioral plasticity. 2- To derive region and temporally specific mutations for genes that affect long-term memory for contextual conditioning. We propose to use the loxP/Cre recombinase system to control the cell types, brain regions and temporal expression of the mutations isolated in aim 1. The resulting mice will be tested for memory deficits and will also be studied in Projects 2 and 3. 3- To uncover cortical molecular mechanisms underlying the turnover and stability of spines in the anterior cingulate. Plasticity, including behavioral plasticity (i.e. remote memory), is thought to involve changes in neuronal structure required for consolidation and stability of stored information. We propose to use 2-photon scanning confocal in vivo imaging to examine whether mutations that affect remote memory also affect turnover and stability of spines in cortical regions required for remote memory (i.e. anterior cingulate) in trained and untrained (contextual conditioning) mutants and controls. These studies will parallel related imaging studies carried out in Projects 2 and 3. All together, the studies described here and related studies in Projects 2 and 3 will unravel fundamental molecular, cellular and structural mechanisms of how the neocortex encodes and stores information. These findings will have a key impact on how we study and treat disorders associated with emotional memory.