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: 8038266
• 负责人: ANDREW R TAPPER
• 金额: $ 40.4万
• 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 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8038266
• 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; Health; High Pressure Liquid Chromatography; Injection of therapeutic agent; Interneurons; Ligands; Measures; Mediating; Microdialysis; Midbrain structure; Movement; Movement Disorders; Mus; 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; cholinergic; design; dopaminergic neuron; in vivo; mouse model; neuronal cell body; neurotransmission; neurotransmitter release; nicotinic receptor beta2; 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）：帕金森病是由黑质多巴胺能神经元进行性死亡导致基底神经节多巴胺释放中断引起的。流行病学数据表明帕金森病在吸烟者中不太普遍。此外，动物研究发现，尼古丁（烟草烟雾的成瘾成分）可保护DA能神经元免受化学损伤，这种作用可能是由神经元烟碱乙酰胆碱受体（nAChR）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，设计了一种新的小鼠品系，其在烟碱受体α-4亚基的推定孔区域内表达单点突变Leu 9 'Ala。该突变使得含α-4（“α-4 *”）的nAChR对激动剂敏感50倍，从而允许分离和扩增涉及α-4 * nAChR的行为和生理表型。最近的研究表明，α-4 β-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，通常负调节活性。初步数据表明，Leu 9 'Ala小鼠中D2样受体的激活可诱发在野生型动物中不发生的帕金森病症状。具体目的1检验了Leu 9 'Ala帕金森病表型由D2样多巴胺受体的激活引起并且依赖于α-4 * nAChR调节的假设。这将通过向小鼠施用不同的多巴胺和烟碱受体拮抗剂并测定帕金森病表型严重程度来完成。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测试了Leu 9 'Ala小鼠中的D2活化揭示了中脑和/或纹状体神经元中Gi/o偶联受体与α-4 * nAChR之间的功能性相互作用的假设。这将通过测量D2激活前后神经元活性和烟碱反应的变化来实现。预期来自所提出的实验的结果将不仅提供新的药理学、可逆的帕金森病小鼠模型，而且还增加对烟碱受体介导的DA能神经传递调节的理解。公共卫生相关性预计本研究的结果将提供一种新的帕金森病药理学可逆小鼠模型。此外，这种小鼠模型应该有助于阐明在正常和患病状态下自主运动的重要神经元机制。