Nicotinic-dopamine receptor interaction in a novel Parkinsonian mouse model.

新型帕金森病小鼠模型中烟碱-多巴胺受体的相互作用。

• 批准号: 7692288
• 负责人: ANDREW R TAPPER
• 金额: $ 32.35万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-30 至 2012-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7692288
• 关键词: Acetylcholine; Address; Affect; Affinity; Age; Agonist; Animals; Basal Ganglia; Behavioral; Bilateral; Biological Assay; Bradykinesia; Brain region; Catalepsy; Cations; Cessation of life; Chemicals; Corpus striatum structure; DRD2 gene; Data; Disease; Dopamine; Dopamine Antagonists; Dopamine D2 Receptor; Dopamine Receptor; Dorsal; Engineering; Epidemiology; G-Protein-Coupled Receptors; Genetic; High Pressure Liquid Chromatography; Injection of therapeutic agent; Interneurons; Ligands; Measures; Mediating; Microdialysis; Midbrain structure; Movement; Movement Disorders; Mus; Muscle Rigidity; Mutation; Neurons; Neuroprotective Agents; Nicotine; Nicotinic Receptors; Parkinson Disease; Parkinsonian Disorders; Phenotype; Physiological; Point Mutation; Population; Presynaptic Terminals; Quinpirole; Receptor Activation; Rest Tremor; Severities; Slice; Smoker; Substantia nigra structure; Symptoms; Testing; Tobacco smoke; Tremor; Wild Type Mouse; abstracting; cholinergic; design; dopaminergic neuron; in vivo; mouse model; neuronal cell body; neurotransmission; neurotransmitter release; novel; pars compacta; receptor; receptor coupling; research study; response

DESCRIPTION (provided by applicant): Parkinson's disease is caused by the disruption of dopamine release in basal ganglia due to the progressive death of dopaminergic neurons in substantia nigra. Epidemiological data indicate Parkinson's disease is less prevalent in smokers. In addition, animal studies have found that nicotine, the addictive component of tobacco smoke, protects DAergic neurons from chemical insult and that this effect is likely mediated by neuronal nicotinic acetylcholine receptors (nAChRs). How do nAChRs modulate DA neurotransmission and which nAChR subtypes are involved? To address these questions a novel mouse line was engineered expressing a single point mutation, Leu9'Ala, within the putative pore region of the nicotinic receptor alpha-4 subunit. This mutation renders alpha-4-containing ("alpha- 4*") nAChRs 50-fold more sensitive to agonist allowing for the isolation and amplification of behavioral and physiological phenotypes that involve alpha-4* nAChRs. Recent studies suggest that alpha-4 beta- 2* nAChRs may functionally interact directly with D2-like receptors; G-protein coupled receptors that are expressed in midbrain and striatal neurons and, normally, negatively regulate activity. Preliminary data indicate that activation of D2-like receptors in Leu9'Ala mice elicits Parkinsonian symptoms that do not occur in wild-type animals. Specific aim 1 tests the hypothesis that the Leu9'Ala Parkinsonian phenotype is caused by activation of a D2-like dopamine receptor and is dependent on alpha-4* nAChR modulation. This will be done by administering different dopamine and nicotinic receptor antagonists to mice and assaying the Parkinsonian phenotype severity. Specific aim 2 tests the hypothesis that the interaction takes place in substantia nigra and/or stratum. In specific aim 3, in vivo microdialysis will be utilized to assay dopamine and acetylcholine release. Finally, specific aim 4 tests the hypothesis that D2 activation in Leu9'Ala mice uncovers a functional interaction between Gi/o coupled receptors and alpha-4* nAChRs in midbrain and/or striatal neurons. This will be achieved by measuring changes in neuron activity and nicotinic responses before and after D2 activation. It is anticipated that the results from the proposed experiments will not only provide a new pharmacological, reversible, Parkinson's disease mouse model, but, also increase understanding of nicotinic receptor mediated modulation of DAergic neurotransmission. PUBLIC HEALTH RELEVANCE It is anticipated that the results from this study will provide a new pharmacological, reversible mouse model of Parkinson's disease. In addition, this mouse model should help elucidate underlying neuronal mechanisms important for voluntary movement in normal and diseased states.

描述（由申请人提供）：帕金森病是由于黑质中的多巴胺能神经元进行性死亡而导致基底神经节中的多巴胺释放中断而引起的。流行病学数据表明，帕金森病在吸烟者中较少见。此外，动物研究发现，烟草烟雾中的成瘾成分尼古丁可以保护 DAergic 神经元免受化学损伤，并且这种作用可能是由神经元烟碱乙酰胆碱受体 (nAChRs) 介导的。 nAChR 如何调节 DA 神经传递以及涉及哪些 nAChR 亚型？为了解决这些问题，我们设计了一种新型小鼠品系，在烟碱受体 α-4 亚基的推定孔区域内表达单点突变 Leu9'Ala。该突变使含有 α-4（“α-4*”）的 nAChR 对激动剂的敏感性提高 50 倍，从而可以分离和扩增涉及 α-4* nAChR 的行为和生理表型。最近的研究表明 alpha-4 beta-2* nAChR 可能在功能上直接与 D2 样受体相互作用； G 蛋白偶联受体在中脑和纹状体神经元中表达，通常负向调节活性。初步数据表明，Leu9'Ala 小鼠中 D2 样受体的激活会引发野生型动物中不会出现的帕金森病症状。具体目标 1 检验以下假设：Leu9'Ala 帕金森病表型是由 D2 样多巴胺受体激活引起的，并且依赖于 alpha-4* nAChR 调节。这将通过给小鼠施用不同的多巴胺和烟碱受体拮抗剂并测定帕金森表型的严重程度来完成。具体目标 2 检验相互作用发生在黑质和/或地层中的假设。在具体目标 3 中，将利用体内微透析来测定多巴胺和乙酰胆碱的释放。最后，具体目标 4 检验了这一假设：Leu9'Ala 小鼠中的 D2 激活揭示了中脑和/或纹状体神经元中 Gi/o 偶联受体与 α-4* nAChR 之间的功能相互作用。这将通过测量 D2 激活前后神经元活动和烟碱反应的变化来实现。预计所提出的实验结果不仅将提供新的药理学、可逆的帕金森病小鼠模型，而且还将增加对烟碱受体介导的 DAergic 神经传递调节的理解。公共卫生相关性 预计这项研究的结果将提供一种新的药理学、可逆的帕金森病小鼠模型。此外，该小鼠模型应有助于阐明对正常和患病状态下的随意运动很重要的潜在神经元机制。