The Septohippocampal System: Regulation by Neurotrophins

描述（由申请人提供）：细胞和亚细胞机制的可塑性变化是神经行为表现的关键决定因素；神经系统功能的。我们拟探讨神经生长因子（NGF）对中隔海马（S-H）系统的调控作用。核心假设是，小鼠海马内NGF功能的增强在短期内增强了间隔胆碱能神经元的活性，并在长期内导致医学间隔/斜带核（MS/nDB）和海马的同步重组，从而沿S-H系统传递神经。为了验证这一假设，我们将使用具有靶向海马内NGF功能增益的转基因小鼠作为实验模型。实验包括膜片钳记录、免疫组织化学和pcr扩增免疫反应性检测（PADI），分为三个特定目的。特异性目的1将验证gaba能MS/nDB神经元受MS/nDNB中胆碱能活性维持的毒碱性张力调节的假设。特异性目的2将验证一个假设，即海马中NGF的靶向激活和表达增加导致MS/nDNB神经元性质的变化，这与增强的毒毒碱张力一致，从而沿着S-H途径活动。具体目标3将采用中隔海马共培养系统来验证NGF的靶向激活是时间和活动依赖的假设。测试这些假设的固有概念是特定的细胞和分子变化可以与NGF激活相关。因此，除了电生理实验外，候选蛋白质将通过基于pcr的蛋白质检测技术在激光捕获显微解剖分离的单个神经元中进行分析。总的来说，该项目将有助于我们了解神经系统中ngf诱导的可塑性的细胞和分子基础，并探索靶向基因转移作为一种潜在的治疗策略的价值，以改善各种神经退行性疾病中认知功能障碍的衰弱后果。

DESCRIPTION (provided by applicant): Plastic changes in cellular and subcellular mechanisms are critical determinants of neurobehavioral manifestations; of nervous system function. We propose to investigate the regulation of the septohipppocampal (S-H) system by nerve growth factor (NGF). The central hypothesis is that an intrahippocampal gain of NGF function in mice enhances activity of septal cholinergic neurons in the short term and, in the long term, leads to synantic reorganization in both the medical septum/nucleus of Diagonal Band (MS/nDB) and hippocampus and, thereby neurotransmission along the S-H system. To test this hypothesis, we will use as experimental model transgenic mice harboring a targeted intrahippocampal gain of NGF function. The experiments, incorporating patch clamp recording, immunohistochemistry and PCR-Amplified Detection of Immunoreactivity (PADI), are organized into three specific aims. Specific Aim 1 will test the hypothesis that GABAergic MS/nDB neurons are under regulation of a muscarinic tone that is maintained by cholinergic activity in the MS/nDNB. Specific Aim 2 will test the hypothesis that a targeted activation and increase in the expression of NGF in the hippocampus leads to changes in the properties of MS/nDNB neurons that are consistent with an augmented muscarinic tone and thus activity alongthe S-H pathway. Specific Aim 3 will employ a septohippocampal coculture system to test the hypothesis that the targeted activation of NGF is time- and activity-dependent. Inherent in testing these hypothesis is the notion that specific cellular and molecular changes can be correlated with NGF activation. Thus, in addition to the electrophysiological experiments, candidate proteins will be analyzed by a PCR-based protein detection technique in single neurons isolated by laser capture microdissection. Overall, this project will contribute to our understanding of the cellular and molecular bases underlying NGF-induced plasticity in the nervous system and explore the value of targeted gene transfer as a potential therapeutic strategy to ameliorate the debilitating consequences of cognitive dysfunction as seen in a variety of neurodegenerative conditions.