Protein Kinases in Synaptic Plasticity

描述（由申请人提供）：脊椎动物突触可塑性的一个有前景且被广泛研究的例子是长期增强（LTP），即在短暂的突触前和突触后活动一致后出现的持续突触增强。研究表明，LTP的细胞和分子机制将解释学习、记忆、发育突触特异性、疼痛、神经元死亡、癫痫和痴呆等生理和病理现象。最近的一些研究表明，调节突触传递AMPA受体（-Rs）是LTP的一个关键方面。在这里，我们将研究控制AMPA-Rs突触递送的分子机制。要验证的中心假设是，蛋白激酶通过减轻AMPA-Rs突触外滞留来驱动AMPA-Rs进入突触。我们将研究两种蛋白激酶PKA和CaMKII在控制保留相互作用中的作用，这些相互作用使AMPA-Rs保持在胞外。这将在发育早期，当GluR4控制突触传递时，以及在生命后期，当突触传递由GluR1控制时进行检查。将使用几种互补的方法，包括分子生物学、电生理学、gfp标记受体的双光子成像以及光学和电子显微镜下的免疫组织化学。这些研究将使用器官型大鼠海马切片。具体目的是确定SA1: PKA在出生后发育早期控制glur4 - econtaining - ampa - r突触传递的机制。SA2: PKA在生命后期控制CaMKII驱动的glur1 - ampa - r的突触传递。SA3: PKA控制生命后期LTP的产生。SA4: AMPA-Rs的胞外保留受蛋白相互作用调节。

DESCRIPTION (provided by applicant): 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. A number of recent studies indicate that regulated synaptic delivery of AMPA receptors (-Rs) is a critical aspect of LTP. Here we will examine molecular mechanisms controlling the regulated synaptic delivery of AMPA-Rs The central hypothesis to be tested is that protein kinases drive AMPA-Rs to synapses by relieving their extrasynaptic retention. We will examine the role of two protein kinases, PKA and CaMKII, in controlling retention interactions that keep AMPA-Rs extrasynaptically. This will be examined early in development, when GluR4 controls synaptic delivery, and later in life, when synaptic delivery is controlled by GluR1. Several complementing methodologies will be used, including molecular biology, electrophysiology, two-photon imaging of GFP-tagged receptors, and immunohistochemistry with light and electron microscopy. These studies will use organotypic rat hippocampal slices. The specific aims are to determine the mechanism by which: SA1: PKA controls synaptic delivery of GluR4-eontaining-AMPA-R early in postnatal development. SA2: PKA controls synaptic delivery of GluR1-containing-AMPA-R driven by CaMKII later in life. SA3: PKA controls generation of LTP later in life. SA4: extrasynaptic retention of AMPA-Rs is regulated by protein-protein interactions.