DEVELOPMENTAL REGULATION OF GLUTAMATE RECEPTOR FUNCTION

描述：申请者使用的是上级的表层 用丘脑(SSC)研究啮齿动物神经之间的关系 N-甲基-D-天冬氨酸受体(NR)活性和电流时程的缩短 发生在开发过程中。申请人已经证明了突触的NR电流 大鼠SSC衰变时间骤减(24小时) NR亚基NR1和NR2a的转录和蛋白的变化。这 下降发生在睁眼前和视网膜睫状核的末尾 精致。我们还证明了GABA能抑制，它可以 异向调节NR功能，开始于晚些时候、睁开眼睛和 在皮质-皮质地图精化过程中。然而，慢性应用 从P8开始的对SSc的NMDA增加GABA能异常抑制 并扰乱了NR的正常调控模式。这项提议将 检验这项工作中出现的四个假说：(1)亚突触 NR的翻译后蛋白修饰或突触下调节 亚基的掺入决定了NR电流的速度 衰变时间减少，(2)NR2A亚单位水平的增加 有助于这种变化，(3)NR激活触发NR电流 衰变纽带减少和/或NR亚基组成改变 GABA能抑制增强是对NR激活的特异性反应 在有限的发展关键期。 为了检测NMDA处理的大鼠SSC转录本和蛋白质的变化， 提案将使用核糖核酸酶保护分析、竞争性聚合酶链式反应、免疫印迹、 免疫细胞化学、免疫沉淀和细胞分级程序。 全细胞膜片钳切片和分离的SSC培养 在培养过程中结合钙离子成像，将其用于检测NR的功能。在……里面 此外，野生型和NR2A基因敲除小鼠的SSC将被检测 确定该亚基是否有助于NR电流的快速变化 基因敲除的GABA系统是否由于 预计这种突变会导致活性的增加。 申请人寻求对相互作用的机械性理解 神经递质相关基因产物和活性在神经发育中的作用 神经回路。这些发现应该有助于治愈或治疗 儿童精神障碍被认为与环境或表观遗传有关 组件。这些症状从轻微的言语和语言缺陷到 破坏性的和普遍的神经疾病，如癫痫、脑部疾病 瘫痪和自闭症。

DESCRIPTION: The applicant is using the superficial layers of the superior colliculus (sSC) in rodents to study the relationship between neural activity and the reduction of NMDA receptor (NR) current duration that occurs during development. The applicant has shown that synaptic NR current decay time decreases abruptly (24hrs) in the rat sSC in association with changes in both transcripts and protein for NR subunits NR1 and NR2A. This decrease occurs before eye opening and at the end of retinocollicular map refinement. We have also shown that GABAergic inhibition, which can modulate NR function heterosynaptically, begins later, after eye-opening and during cortico-collicular map refinement. However, chronic application of NMDA to the sSC beginning at P8 increases GABAergic inhibition abnormally early and disrupts the normal pattern of NR regulation. This proposal will test four hypotheses that emerge from this work: (1) that subsynaptic post-translational protein modification or subsynaptic regulation of NR subunit incorporation is responsible for the speed with which NR current decay time decreases, (2) that the increase in NR2A subunit level also contributes to this change, (3) that NR activation triggers the NR current decay tie decrease and/or NR subunit composition changes and (4) that increased GABAergic inhibition is a specific response to NR activation during a restricted developmental critical period. To assay transcript and protein changes in NMDA-treated rat sSC, the proposal will use RNase protection assays, competitive PCR, immunoblotting, immunocytochemistry, immunoprecipitation and cell fractionation procedures. Whole-cell patch clamping in slices and in a dissociated sSC culture, along with calcium imaging in culture, will be used to assay NR function. In addition, the sSC of wildtype and NR2A knockout mice will be examined to determine if this subunit contributes to rapid NR current changes and whether the GABA system of the knockout has up-regulated as a result of increases in activity that a re expected to result from this mutation. The applicant seeks a mechanistic understanding of the interaction of neurotransmission-related gene products and activity in the development of neural circuits. The findings should facilitate cures or treatments for disorders of childhood thought to have an environmental or epigenetic component. These range from mild speech and language deficits to devastating and prevalent neurological diseases such as epilepsy, cerebral palsy and autism.