MOLECULAR BASIS OF STRIATAL D1 SUPERSENSITIVITY

多巴胺受体超敏可能是限制运动障碍的原因 左旋多巴治疗帕金森病(PD)。其机制尚不清楚。 人和大鼠黑质毁损后，d1 尽管受体数量和受体数量没有变化，但受体超敏反应仍在发展 亲和力。我们的初步数据表明，黑质病变改变了d1- CAMP或Ca~(++)调节的信号转导调节 途径，或两者都有，表明改变了细胞内的假说 信号转导是D1受体超敏反应的基础。这 应用程序建议对这一假设进行检验。 目标1将确定黑质后d1是否超敏 破坏与cAMP中分子表达的改变有关 用Northern分析和原位杂交研究信号转导途径 杂交。目标2将确定钙离子调节的信号转导 通过检测D1超敏感性，通路可能是重要的。 阻断钙调节通路的不同步骤对细胞周期蛋白D_1的影响 原代纹状体细胞CREB磷酸化和Fos的表达 文化。目标3将确定反义硫代磷酸 寡核苷酸可以特异性地灭活信号转导分子 在原代培养的纹状体细胞中，D1的功能是重要的。目标4将 检验先前确定的因子上调的假设 实验在d1过敏症中起因果作用 脑内6-羟基多巴胺损毁大鼠的阻断旋转行为 注射反义硫代寡核苷酸。 成功完成拟议的实验将提供 纹状体对多巴胺能去神经适应机制的探讨 尤其是对D1超敏感。这一结果可能会显示出新的 预防或治疗帕金森病患者左旋多巴引起的运动障碍的途径。

Dopamine receptor supersensitivity may underlie the dyskinesias that limit levodopa treatment for Parkinson's disease (PD). Its mechanism is unknown. Following destruction of the substantia nigra in human and rat, D1 receptor supersensitivity develops despite unchanged receptor number and affinity. our preliminary data indicate that nigral lesions alter D1- mediated regulation of cAMP- or Ca++-regulated signal transduction pathways, or both, suggesting the hypothesis that altered Intracellular signal transduction underlies D1 receptor supersensitivity. This application proposes to test this hypothesis. Aim 1 will determine whether D1 supersensitivity following nigral destruction is associated with altered expression of molecules in the cAMP signal transduction pathway, using Northern analyses and in situ hybridization. Aim 2 will determine if Ca++-regulated signal transduction pathways could be important for D1 supersensitivity by examining the effects of blocking different steps in Ca++-regulated pathways on D1- mediated CREB phosphorylation and Fos expression in primary striatal cell culture. Aim 3 will determine whether antisense phosphorothioate oligonucleotides can specifically inactivate signal transduction molecules important for D1 function in primary striatal cell culture. Aim 4 will test the hypothesis that upregulation of factors identified in earlier experiments plays a causal role in D1 supersensitivity by attempting to block rotational behavior in 6-OHDA-lesioned rats with intracerebral infusions of antisense phosphorothioate oligonucleotides. Successful completion of the proposed experiments will provide insight into the mechanisms of striatal adaptation to dopaminergic denervation and, in particular, D1 supersensitivity. The results may suggest new avenues for prevention or treatment of levodopa-induced dyskinesias in PD.