ETHANOL, NEUROSTEROIDS & HIPPOCAMPAL PLASTICITY

乙醇、神经类固醇

• 批准号: 7934684
• 负责人: CHARLES F ZORUMSKI
• 金额: $ 37.44万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-20 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7934684
• 关键词: Acute; Adverse drug effect; Adverse effects; Alcohol abuse; Alcoholic Intoxication; Alcohols; Aminobutyric Acids; Ataxia; Behavioral; Cessation of life; Chronic; Cognition; Communication; Complex; Dementia; Ethanol; Euphoria; Exhibits; Exposure to; Generations; Glutamate Receptor; Glutamates; Goals; Hippocampus (Brain); Hour; Individual; Intoxication; Laboratories; Life; Long-Term Depression; Long-Term Effects; Long-Term Potentiation; Mediating; Memory; Mental Depression; N-Methyl-D-Aspartate Receptors; N-Methylaspartate; Nervous system structure; Neurobehavioral Manifestations; Neurons; Pharmaceutical Preparations; Process; Production; Rattus; Reaction Time; Risk Factors; Role; Sedation procedure; Slice; Synapses; Synaptic Transmission; Synaptic plasticity; Testing; United States; Ventilatory Depression; alcohol abuse therapy; alcohol effect; alcohol exposure; binge drinking; cognitive function; drug of abuse; gamma-Aminobutyric Acid; ifenprodil; memory process; neurosteroids; novel; prevent; public health relevance; receptor; research study; synaptic function; synaptic inhibition; transmission process

DESCRIPTION (provided by applicant): Acute ethanol intoxication is associated with behavioral and cognitive symptoms that include problems with memory processing. In some cases, ethanol intoxication can result in a complete inability to process new information, a condition known as a "blackout". Understanding how ethanol alters cognition and memory is important for determining ways to protect the nervous system from the short- and long-term adverse effects of the drug. Although the mechanisms underlying memory processing in the mammalian nervous system are not completely understood, present evidence suggests that use-dependent forms of synaptic plasticity at glutamate synapses in the hippocampus, including long-term potentiation (LTP) and long-term depression (LTD), are relevant. For the past several years our laboratory has examined the acute effects of ethanol on synaptic transmission and synaptic plasticity in the CA1 region of rat hippocampal slices. We have found that ethanol acutely inhibits a specific subtype of synaptic N-methyl-D-aspartate receptor (NMDAR) that is also inhibited by the NR1/NR2B antagonist, ifenprodil. Block of LTD by ethanol correlates with the block of these synaptic NMDARs. Effects on LTP are more complex and persistent, and involve effects on gamma-aminobutyric acid (GABA)-mediated inhibitory transmission. In recent studies, we found that GABA-enhancing neurosteroids contribute to the ability of ethanol to block LTpreliminary Additionally, the ability of ethanol to block LTP depends upon how ethanol is administered, with acute applications of high concentrations blocking LTP and slower step-wise increases in ethanol concentration to high levels resulting in a form of acute tolerance. In this project, we will extend these initial observations and pursue three sets of studies that will examine: 1. How GABAergic neurosteroids contribute to acute effects of ethanol on LTP; 2. Factors contributing to the longer-lived (several hour) effects of ethanol on LTP; and 3. Factors contributing to the acute tolerance to ethanol-mediated LTP inhibition following slower increases in ethanol concentration. These studies will be done in rat hippocampal studies and will focus on the effects of ethanol and related modulators on glutamatergic and GABAergic transmission. The long-term goal of these studies is to identify ways to protect the nervous system from the adverse effects of ethanol on synaptic function and cognition. PUBLIC HEALTH RELEVANCE Alcohol is one of the most commonly abused drugs in the United States and is associated with both acute and long-term problems with memory processing. The goal of this project is to determine how alcohol alters communication between nerve cells to impair memory formation with the hope of developing better treatments for alcohol-induced memory problems.

描述（由申请人提供）：急性乙醇中毒与行为和认知症状有关，包括记忆处理问题。在某些情况下，乙醇中毒可能会导致完全无法处理新信息，即一种称为“停电”的条件。了解乙醇如何改变认知和记忆对于确定保护神经系统免受药物短期和长期不良影响的方法很重要。尽管尚未完全了解哺乳动物神经系统中记忆过程的基础机制，但目前的证据表明，海马中谷氨酸突触的使用依赖性突触可塑性形式，包括长期增强（LTP）和长期抑郁（LTD）（LTD）。在过去的几年中，我们的实验室研究了乙醇对大鼠海马切片CA1区域突触传播和突触可塑性的急性影响。我们发现乙醇急性抑制突触N-甲基-D-天冬氨酸受体（NMDAR）的特定亚型，该亚型也受到NR1/NR2B拮抗剂Ifenprodil的抑制。乙醇的LTD块与这些突触NMDAR的块相关。对LTP的影响更加复杂和持续，并且涉及对γ-氨基丁酸（GABA）介导的抑制性传播的影响。在最近的研究中，我们发现增强GABA的神经类固醇有助于乙醇阻止LT.的能力，另外，乙醇阻断LTP的能力取决于乙醇的施用，而高浓度LTP的急性应用和较慢的速度促进乙醇浓度的急性稳定性增加，从而使乙醇的浓度增加了高度的高度倾斜度。在这个项目中，我们将扩展这些最初的观察结果，并进行三组研究，这些研究将研究：1。加巴能神经类固醇如何促进乙醇对LTP的急性影响； 2。导致乙醇对LTP的寿命长（几个小时）影响的因素；和3。导致乙醇介导的LTP抑制急性耐受性降低后乙醇浓度升高后急性耐受性的因素。这些研究将在大鼠海马研究中进行，并将集中于乙醇和相关调节剂对谷氨酸能和GABA能传播的影响。这些研究的长期目标是确定保护神经系统免受乙醇对突触功能和认知的不利影响的方法。公共卫生相关性酒精是美国最常见的滥用药物之一，并且与记忆加工的急性和长期问题有关。该项目的目标是确定酒精如何改变神经细胞之间的通信以损害记忆形成，以期为酒精引起的记忆问题开发更好的治疗方法。