The role of dopaminergic transmission in the development of manic-like behaviors

多巴胺能传递在躁狂样行为发展中的作用

• 批准号: 7913994
• 负责人: SADE MONIQUE SPENCER
• 金额: $ 2.84万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7913994
• 关键词: Animals; Antibodies; Anxiety; Back; Behavior; Behavioral; Binding; Biological Assay; Bipolar Disorder; Brain; Brain region; CREB1 gene; Circadian Rhythms; Corpus striatum structure; Darkness; Development; Dopamine; Etiology; Gene Expression; Genes; Genetic Transcription; Goals; High Pressure Liquid Chromatography; Hour; Human; Lithium; Manic; Manic Disorder; Mental Depression; Mental disorders; Methods; Modeling; Molecular; Mood Disorders; Moods; Motor Activity; Mus; Mutant Strains Mice; Mutation; Neurons; Nucleus Accumbens; Patients; Pattern; Pharmaceutical Preparations; Phenotype; Play; Potassium Channel; Proteins; Publishing; Regulation; Rewards; Role; Simplexvirus; System; Testing; Time; Tyrosine 3-Monooxygenase; Ventral Tegmental Area; Virus; Western Blotting; Work; alpha-Methyltyrosine; chromatin immunoprecipitation; circadian pacemaker; design; dopamine system; gene function; improved; mutant; neurotransmission; promoter; protein expression; public health relevance; research study; transcription factor; transmission process

DESCRIPTION (provided by applicant): There is a growing body of evidence to suggest that mood disorders, such as bipolar disorder, may be associated with disruptions in circadian rhythms. Previous work in our lab has shown that mice with a mutation in their Clock gene, a critical component of the core circadian machinery, display a behavioral phenotype similar to human patients in the manic phase of bipolar disorder. Importantly, when a functional Clock is introduced into the Ventral Tegmental Area (VTA), this regional rescue is sufficient to restore some of the behaviors back to wild type levels offering an important clue as to where Clock function may be important for modulating mood-related behaviors. The VTA is an important brain region of the limbic dopaminergic circuit providing projections to brain regions such as the Nucleus Accumbens (NAc). Understanding how circadian genes may interact with the dopamine system to regulate mood and reward related behaviors is critical in designing new treatments for affective disorders. This proposal seeks to characterize this interaction using the Clock mutant mice as a model of mania. In specific aim 1, we plan to determine the effects of disruption of Clock gene function on the rhythmic expression patterns of TH in the VTA and the NAc. We have preliminary evidence suggesting the dopaminergic system may be dysregulated in the Clock mutant mice. We will examine both the diurnal and circadian rhythms by assaying gene expression over six time points under both 12 hour light-dark (LD) and constant darkness (DD) conditions. Gene expression changes may or may not be mirrored by changes at the protein level, therefore we will assay for these alterations in the protein expression of Tyrosine Hydroxylase (TH) and p-TH (ser 31) by western blot. We will also examine the total levels of striatal dopamine by high performance liquid chromatography. We will repeat these experiments in the presence of lithium to determine whether molecular alterations are rescued by the treatment as we have observed with the behavioral changes in the Clock mutants. In specific aim 2, we will try to determine if the Clock mutation alters the regulation of the TH gene and whether the TH promoter is a target of lithium's action. First, we will assay for changes in rhythmic gene expression of transcription factors Clock, Bmal1, and Creb which are implicated in regulation of TH transcription. Additionally, we will investigate changes in the protein levels of CLOCK, BMAL1, CREB, and p-CREB (ser 133) over six time points. We will also directly examine binding at the TH promoter by performing Chromatin Immunoprecipitation assays using antibodies specific for CLOCK, BMAL1, and CREB. These experiments will be performed both with and without lithium treatment to determine if the drug alters activity at the TH promoter in the Clock mutant mice. In specific aim 3, we plan to establish a role for dopamine in the development of the manic-like behaviors of the Clock mutant mice. We will employ two different methods to manipulate the dopamine system in an effort to modulate the behavior of the Clock mutants. First, we will systemically administer Alpha-methyl-p-tyrosine to inhibit TH activity and decrease dopamine levels followed by a battery of behavioral experiments including locomotor activity, anxiety, and depression-related behaviors. We will also manipulate the firing rate of VTA neurons by delivering a K+ channel virus, HSV Kir2.1, directly into the VTA. This construct has been previously published and verified. These animals will similarly be tested for their mood-related behaviors. PUBLIC HEALTH RELEVANCE: The circadian clock is increasingly being implicated in the etiology of psychiatric diseases including bipolar mania. The goal of this proposal is to improve our understanding of the role of the circadian clock in the brain's mesolimbic dopaminergic circuit and the role that disruption of circadian genes plays in dysregulation of dopaminergic neurotransmission.

描述（由申请人提供）：越来越多的证据表明，情绪障碍（例如躁郁症）可能与昼夜节律中断有关。我们实验室中的先前工作表明，在双相情感障碍的躁狂阶段，其时钟基因（核心圆形机械的关键成分）中有突变的小鼠表现出与人类患者相似的行为表型。重要的是，当将功能时钟引入腹侧对段区域（VTA）时，该区域救援就足以将某些行为恢复回到野生型水平，从而提供了有关时钟功能可能对调节情绪相关行为很重要的重要线索。 VTA是边缘多巴胺能回路的重要大脑区域，可为大脑区域（例如伏隔核（NAC））提供投影。了解昼夜节律基因如何与多巴胺系统相互作用以调节情绪和奖励相关行为对于为情感障碍设计新的治疗方法至关重要。该提案旨在使用时钟突变小鼠作为躁狂模型来表征这种相互作用。在特定目标1中，我们计划确定时钟基因功能中断对VTA和NAC中Th节奏表达模式的影响。我们有初步证据表明，在时钟突变小鼠中可能会失去多巴胺能系统。我们将通过在12小时浅黑暗（LD）和恒定的黑暗（DD）条件下测定六个时间点的基因表达来检查昼夜节奏和昼夜节律。基因表达的变化可能会通过蛋白质水平的变化反映，因此我们将测定这些改变酪氨酸羟化酶（Th）（Th）和P-Th（Ser 31）的蛋白质表达的改变。我们还将通过高性能液相色谱检查纹状体多巴胺的总水平。我们将在存在锂的情况下重复这些实验，以确定是否通过钟突变体的行为变化来挽救分子改变。在特定目标2中，我们将尝试确定时钟突变是否改变了TH基因的调节，以及TH启动子是否是锂作用的目标。首先，我们将测定转录因子时钟，BMAL1和CREB的节奏基因表达的变化，这与TH转录的调节有关。此外，我们将在六个时间点上研究时钟，BMAL1，CREB和P-CREB（SER 133）的蛋白质水平的变化。我们还将通过使用针对时钟，BMAL1和CREB的抗体进行染色质免疫沉淀测定法直接检查TH启动子的结合。这些实验将在有没有锂处理的情况下进行，以确定药物在时钟突变小鼠中的启动子的活性是否改变。在特定的目标3中，我们计划在钟突变小鼠的躁狂样行为发展中确立多巴胺的作用。我们将采用两种不同的方法来操纵多巴胺系统，以调节时钟突变体的行为。首先，我们将系统地施用α-甲基-P-酪氨酸，以抑制TH活性并降低多巴胺水平，然后是一系列行为实验，包括运动活性，焦虑和与抑郁症相关的行为。我们还将通过将K+通道病毒HSV KIR2.1（直接输送到VTA）传递到VTA来操纵VTA神经元的发射速率。此结构先前已发表和验证。这些动物将同样测试与情绪相关的行为。 公共卫生相关性：昼夜节律越来越涉及精神病的病因，包括双极躁狂症。该提案的目的是提高我们对昼夜节律时钟在大脑中唇胶多巴胺能电路中的作用的理解，以及昼夜节律基因在多巴胺能神经传递失调中起作用的作用。