DEFINING THE ROLE OF CAMKII IN SYNAPTIC PLASTICITY

脊椎动物突触可塑性的一个有前途的和被广泛研究的例子 是长时程增强(LTP)，即持续性突触增强 在短暂的突触前和突触后重合的时期后看到的 活动。有人认为，细胞和分子 负责LTP的机制将阐明生理和 病理现象包括学习、记忆、发育性突触 特异性、疼痛、神经元死亡、癫痫和痴呆症。蜂窝手机 负责产生LTP的信令已经被广泛研究。 先前的研究表明，钙/钙调蛋白依赖蛋白 激酶II(CaMKII)既是产生LTP的必要条件也是充分条件 从而可以调节记忆的形成。 在这里，我们将检查增加的细胞和分子后果 CaMKII活性可能与LTP有关。核心假设是 有待检验的是，突触后CaMKII活性的增加增加了 兴奋性突触上AMPA受体的数量：两者都在突触上 含有和不含有AMPA受体的。我们将对此进行检查 通过包括电生理学在内的几种补充方法， GFP标记受体的双光子成像和免疫组织化学 用光学和电子显微镜观察。这些研究将使用啮齿动物 海马片(急性和器官型)和分离培养 神经元。 了解负责的细胞信号的主要动机 学习和记忆是为了了解和减轻疾病 影响这些功能。为了实现这一目标，我们将研究LTP和 CaMKII在表达突变型PS-1蛋白转基因小鼠中的作用 与阿尔茨海默氏症密切相关。这种蛋白质会扰乱钙离子 动态平衡和我们的初步数据显示这些小鼠有异常的 大型LTP。 SA1：确定CaMKII增加突触的机制(S) AMPA受体功能。 SA2：确定CaMKII是否将沉默的突触转化为正常功能 突触。 SA3：确定树突状细胞胞吐是否在LTP中起作用。 SA4：确定表达FAD突变的小鼠的LTP是否增强 早老素-1。

A promising and widely studied example of vertebrate synaptic plasticity is long-term potentiation (LTP), the persistent synaptic enhancement seen following a brief period of coincident pre- and postsynaptic activity. It has been suggested that the cellular and molecular mechanisms responsible for LTP will elucidate physiological and pathological phenomena including learning, memory, developmental synapse specificity, pain, neuronal death, epilepsy and dementia. The cellular signaling responsible for generating LTP has been studied extensively. Previous studies indicate that calcium/calmodulin-dependent protein kinase II (CaMKII) is both necessary and sufficient to produce LTP and thus may mediate the formation of memories. Here we will examine cellular and molecular consequences of increased CaMKII activity that may contribute to LTP. The central hypothesis to be tested is that increased postsynaptic CaMKII activity increases the number of AMPA receptors at excitatory synapses: both at synapses containing and not containing AMPA receptors. This will be examined with several complementing methodologies including electrophysiology, two photon imaging of GFP-tagged receptors, and immunohistochemistry with light and electron microscopy. These studies will use rodent hippocampal slices (acute and organotypic) and dissociated cultured neurons. A primary motivation to understand the cellular signaling responsible for learning and memory is to understand and alleviate diseases affecting these functions. Toward this goal, we will examine LTP and the role of CaMKII in transgenic mice expressing mutant PS-1, a protein strongly linked to Alzheimer's disease. This protein perturbs calcium homeostasis and our preliminary data show these mice have abnormally large LTP. SA1: To determine the mechanism(s) by which CaMKII increases synaptic AMPA-receptor function. SA2: To determine if CaMKII converts silent synapses into functioning synapses. SA3: To determine if dendritic exocytosis plays a role in LTP. SA4: To determine if LTP is enhanced in mice expressing FAD mutant presenilin-1.