CRCNS: Spatial & Temporal Aspects of cAMP/PKA Signaling Underlying Information

描述（由申请人提供）：海马内的神经元对特定时间和空间模式的刺激进行差异性响应的能力是神经回路中记忆和信息存储的基础。信号转导通路对于信息存储是至关重要的，并且关键信号分子（例如cAMP依赖性蛋白激酶（PKA）信号通路）的改变改变了视丘依赖性学习和被称为长时程增强（L-LTP）的突触可塑性的形式。这些信号通路的改变在神经和精神疾病如酒精中毒、抑郁症、精神分裂症和阿尔茨海默病中起着关键作用。尽管这种临床相关性，很少有人知道信号通路如何不同的时间和空间模式的突触输入。PKA定位于亚细胞区室的A-激酶转运蛋白（AKAP）的动力学提供了一个潜在的机制，这种空间和时间的特异性。我们提出了一个创新的和变革性的一组实验，以调查涉及PKA和AKAP的多蛋白复合物在神经元信息存储和突触可塑性的关键作用。具体目标1.明确蛋白激酶A（PKA）在晚相长时程增强（L-LTP）时间敏感性中的作用。将利用荧光成像、电生理学、生物化学和计算建模来测量LTP诱导刺激后cAMP和PKA活性的水平。这些综合实验和建模将评估NMDA和D1受体信号传导在突触可塑性的持久形式中的作用，并将评估这些受体激活的信号传导通路之间相互作用的时间敏感性。具体目标2.定义海马神经元L-LTP诱导的生化信号机制的空间特异性。将利用计算建模、荧光成像和电生理学方法来测量存在或不存在PKA锚定抑制剂的情况下的L-LTP和cAMP和PKA活性的梯度。这项研究的成功完成将为研究这一途径的改变如何导致精神分裂症和酗酒等精神疾病奠定基础。

DESCRIPTION (provided by applicant): The ability of neurons within the hippocampus to differentially respond to specific temporal and spatial patterns of stimulation underlies the storage of memory and information in neural circuits. Signal transduction pathways are critical for information storage, and alterations in key signaling molecules, such as the cAMP-dependent protein kinase (PKA) signaling pathway, modify both hippocampus-dependent learning and a form of synaptic plasticity known as long-term potentiation (L-LTP). Alterations in these signaling pathways play a critical role in neurological and psychiatric disorders such as alcoholism, depression, schizophrenia and Alzheimer's disease. Despite this clinical relevance, little is known about how signaling pathways respond differentially to distinct temporal and spatial patterns of synaptic input. The dynamics of PKA localization to subcellular compartments by A-Kinase Anchoring Proteins (AKAPs) provides a potential mechanism for such spatial and temporal specificity. We propose an innovative and transformative set of experiments to investigate the critical role of multi-protein complexes involving PKA and AKAPs in neuronal information storage and synaptic plasticity. SPECIFIC AIM 1. Define the role of protein kinase A (PKA) in the temporal sensitivity of late phase long-term potentiation (L-LTP). Fluorescent imaging, electrophysiology, biochemistry and computational modeling will be utilized to measure the level of cAMP and PKA activity after LTP inducing stimuli. These integrated experiments and modeling will evaluate the role of NMDA and D1 receptor signaling in long-lasting forms of synaptic plasticity, and will evaluate the temporal sensitivity of interactions between signaling pathways activated by these receptors. SPECIFIC AIM 2. Define the spatial specificity of biochemical signaling mechanisms underlying L-LTP induction in hippocampal neurons. Computational modeling, fluorescent imaging and electrophysiology approaches will be utilized to measure L-LTP and gradients of cAMP and PKA activity in the presence or absence of inhibitors of PKA anchoring. Successful completion of the research will form the basis for investigating how alterations in this pathway contributes to psychiatric disease such as schizophrenia and alcoholism.