Alcohol and Developing Neuronal Circuits

酒精与发育中的神经元回路

• 批准号: 8607492
• 负责人: Carlos Fernando Valenzuela
• 金额: $ 32.56万
• 依托单位: UNIVERSITY OF NEW MEXICO HEALTH SCIS CTR
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8607492
• 关键词: Abbreviations; Acute; Affect; Alcohol consumption; Alcohols; Binding; Biological Assay; Biotinylation; Brain; Brain-Derived Neurotrophic Factor; Cell membrane; Chronic; Co-Immunoprecipitations; Communication; Dendrites; Development; Disease; Down-Regulation; Electrophysiology (science); Electroporation; Ethanol; Fetal Alcohol Exposure; Fetal Alcohol Spectrum Disorder; Fetal Alcohol Syndrome; Figs - dietary; Functional disorder; Funding; Goals; Hippocampus (Brain); Image; Imaging Techniques; Incidence; Indium; Interneurons; Learning; Light; Long-Term Potentiation; Maintenance; Memory; Memory impairment; Mental disorders; Neonatal; Neurodevelopmental Disorder; Neurons; Patients; Play; Pregnancy; Pregnant Women; Rattus; Recommendation; Regulation; Role; STIM1 gene; Slice; Surface; Synapses; Synaptic plasticity; Techniques; Testing; Therapeutic Intervention; Time; alcohol effect; base; drinking; fetal; granule cell; hippocampal pyramidal neuron; in vivo; mossy fiber; nervous system disorder; novel; novel therapeutic intervention; postnatal; small hairpin RNA; synaptogenesis; transmission process; voltage

DESCRIPTION (provided by applicant): Fetal alcohol spectrum disorder (FASD) is a prevalent disorder characterized by learning and memory deficits that are likely a consequence of alterations in synapse formation, refinement and/or maintenance. During the previous funding period, we showed that 3rd trimester-equivalent ethanol (EtOH) exposure alters activity- dependent plasticity mechanisms that are essential for synapse maturation. In the most recent of these studies, we demonstrated that EtOH potently inhibits a form of synaptic plasticity that depends on local, retrograde release of BDNF from CA3 pyramidal neuron dendrites that is triggered by activation of L-type voltage-gated Ca2+ channels (L-VGCCs). Our hypothesis is that chronic EtOH exposure during the 3rd trimester equivalent persistently inhibits L-VGCCs, leading to a decrease in synaptic plasticity dependent on local retrograde BDNF release and ultimately causing delayed maturation of CA3 pyramidal neuron synapses. Aim #1 is to test the hypothesis that chronic EtOH causes persistent L-VGCC inhibition by inducing channel degradation via depletion of internal Ca2+ stores and STIM1 binding to 11 subunits. Using slice electrophysiological and Ca2+ imaging techniques, we will assess whether EtOH exposure causes persistent functional inhibition of L-VGCCs. We will also determine whether EtOH exposure decreases plasma membrane expression of L-VGCC subunits using a surface biotinylation assay. Using Ca2+ imaging, co- immunoprecipitation and immunhistochemical techniques, we will investigate if these effects are a consequence of depletion of internal Ca2+ stores and STIM1 binding to CaV11.2/1.3. Aim #2 is to test the hypothesis that chronic EtOH inhibits L-VGCC/BDNF-dependent plasticity at mossy fiber-CA3 pyramidal neuron synapses. At these synapses, L-VGCC-dependent retrograde release of BDNF induces spike timing- dependent long-term potentiation and we will investigate if this form of synaptic plasticity is inhibited by EtOH exposure using slice electrophysiological techniques. Aim #3 is to test the hypothesis that EtOH-induced inhibition of L-VGCC-dependent retrograde release of BDNF impairs the maturation of interneuron- and MF- CA3 pyramidal neuron synapses using slice electrophysiological and immunohistochemical techniques. We will also use a novel in vivo neonatal electroporation/shRNA experimental paradigm to determine if selective downregulation of L-VGCC or BDNF expression in CA3 pyramidal neurons mimics the effect of chronic EtOH on development of these synapses. Collectively, the proposed studies will define L-VGCC/BDNF dysfunction as a key element in the pathophysiology of FASD, forming the basis for the rational development of therapeutic interventions against this prevalent disorder. Results will also provide strong evidence supporting the recommendation that even light drinking during the 3rd trimester could adversely affect fetal brain development.

描述（由申请人提供）：胎儿酒精谱系障碍（FASD）是一种以学习和记忆缺陷为特征的流行性疾病，其可能是突触形成、细化和/或维持改变的结果。在上一个资助期间，我们发现，第三个学期当量乙醇（EtOH）暴露改变了活动依赖性可塑性机制，这是突触成熟所必需的。在最近的这些研究中，我们证明了乙醇有效地抑制一种形式的突触可塑性，这种可塑性依赖于由L型电压门控Ca 2+通道（L-VGCC）激活触发的CA 3锥体神经元树突的BDNF的局部逆行释放。我们的假设是，慢性EtOH暴露在第三个三个月相当于持续抑制L-VGCC，导致突触可塑性的下降依赖于局部逆行BDNF的释放，并最终导致CA 3锥体神经元突触的成熟延迟。目的#1是检验以下假设：慢性EtOH通过消耗内部Ca 2+储存和STIM 1与11个亚基结合诱导通道降解而引起持续性L-VGCC抑制。使用切片电生理和Ca 2+成像技术，我们将评估乙醇暴露是否会导致L-VGCC的持续功能抑制。我们还将使用表面生物素化测定来确定EtOH暴露是否降低L-VGCC亚基的质膜表达。使用Ca 2+成像、免疫共沉淀和免疫组织化学技术，我们将研究这些效应是否是内部Ca 2+储存耗尽和STIM 1与CaV 11.2/1.3结合的结果。目的#2是检验慢性EtOH抑制苔藓纤维-CA 3锥体神经元突触的L-VGCC/BDNF依赖性可塑性的假设。在这些突触处，BDNF的L-VGCC依赖性逆行释放诱导尖峰时间依赖性长时程增强，并且我们将使用切片电生理技术研究这种形式的突触可塑性是否被EtOH暴露抑制。目的#3是使用切片电生理学和免疫组织化学技术来检验以下假设：EtOH诱导的BDNF的L-VGCC依赖性逆行释放的抑制损害中间神经元和MF-CA 3锥体神经元突触的成熟。我们还将使用一种新的体内新生儿电穿孔/shRNA实验范式来确定是否选择性下调CA 3锥体神经元中的L-VGCC或BDNF表达模拟慢性EtOH对这些突触发育的影响。总的来说，拟议的研究将L-VGCC/BDNF功能障碍定义为FASD病理生理学的关键因素，为合理开发针对这种流行疾病的治疗干预措施奠定基础。研究结果还将提供强有力的证据支持这一建议，即即使是在妊娠晚期少量饮酒也会对胎儿大脑发育产生不利影响。