BEHAVIORAL AND BIOCHEMICAL CORRELATES OF DOPAMINE RESPON

多巴胺反应的行为和生化相关性

基本信息

批准号：
2392887
负责人：
BENJAMIN WEISS
金额：
$ 20.63万
依托单位：
ALLEGHENY UNIVERSITY OF HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
1987
资助国家：
美国
起止时间：
1987-08-01 至 1999-03-31
项目状态：
已结题

项目摘要

Dopamine (DA) mediates a number of important behavioral and motor events in the central nervous system. These events are governed by one of several subtypes of DA receptors and are influenced by several other neurotransmitter and neuromodulator systems. Past efforts to understand the regulation and function of DA receptors have utilized pharmacological agents that act directly on these receptors. However, in many cases these actions are not specific, as these agents interact with more than one subtype of DA receptor or even interact with receptors for other neurotransmitters. The present study aims to provide a new approach toward the goal of understanding the regulation and function of the DA receptor subtypes, utilizing antisense oligodeoxynucleotides (ODNs) targeted towards the individual mRNAs encoding each of the subtypes of DA receptors. Specifically, it will examine the hypotheses that: a) There is a pool of newly-synthesized DA receptors which constitute the functional pool of these receptors; a hypothesis that may explain why relatively small changes in the total pool of receptors can cause large functional changes in DA responses. To test this hypothesis, we will inhibit the total pool of receptors and then determine the effects of DA antisense ODNs on the rate of recovery of the DA receptors and dopaminergic function; b) There is a feedback control mechanism whereby inhibition of the expression of a specific DA receptor transcript can increase the rate of synthesis of that transcript. This hypothesis will be tested by administering specific DA antisense ODNs for long periods of time and measuring the rate of synthesis of the individual DA receptor mRNAs; c) Certain DA agonists may produce diverse behavioral effects by interacting with different DA receptor subtypes. This hypothesis will be tested by determining the effects of antisense ODNs directed toward the different DA receptor subtypes on the different behaviors mediated by the DA agonist quinpirole. DA receptor mRNAs will be assessed by in situ hybridization histochemistry, and the density and location of DA receptors will be assessed by receptor autoradiography. Biochemical events associated with altered DA activity will also be measured and correlated with the behavioral changes observed. Finally, as the function for the D3, D4 or D5 DA receptors is presently unknown, the effects of ODNs directed toward the mRNAs encoding for these subtypes of DA receptors will be assessed by measuring a battery of behaviors, again correlating these changes with alterations in DA receptors and their mRNAs. In all these studies, great care will be taken to determine whether or not the biological actions observed are, in fact, selective and whether they are due to inhibition of the synthesis of the specific DA receptor subtypes. For example, positive and negative controls for the ODNs will be included in these studies, and the behavioral, biochemical and molecular effects of the antisense ODNs will be examined in great detail, including time- and dose-response studies on the levels of specific DA receptor mRNAs and on the density of DA receptor subtypes. We expect that these studies will not only provide new information on the functional role of the newly-synthesized pool of DA receptors, but will also provide a new strategy for modifying specific DA-mediated events in the central nervous system and may provide the framework for uncovering the function of the newly-discovered subtypes of DA receptors and perhaps for the function of receptors for other neurotransmitter systems. They may also help lay the groundwork for developing novel therapeutic agents for treating certain disorders such as schizophrenia and tardive dyskinesia that are associated with abnormal DA activity.

多巴胺（DA）介导许多重要的行为和运动事件在中枢神经系统中。这些事件由 DA受体的几种亚型，并受其他几个受体的影响神经递质和神经调节剂系统。过去的理解努力 DA受体的调节和功能已使用直接作用于这些受体的药理剂。然而，在许多情况下，这些动作不是具体的，因为这些代理人相互作用具有多种亚型DA受体，甚至与其他神经递质的受体。本研究旨在提供一种新的方法，以理解监管和 DA受体亚型的功能，利用反义针对单个mRNA的寡脱氧核苷酸（ODN）编码DA受体的每个亚型。具体来说，它将检查以下假设：a）有一群新合成的da 构成这些受体功能库的受体；一个假设可以解释为什么总数相对较小的变化受体池可能会导致DA反应发生巨大的功能变化。为了检验这一假设，我们将抑制受体的总库和然后确定DA反义ODN对恢复速率的影响 DA受体和多巴胺能功能； b）有反馈控制机制，通过抑制特定DA的表达受体转录本可以提高合成速率成绩单。该假设将通过管理特定DA来检验长时间的反义ODN并测量单个DA受体mRNA的合成； c）某些DA激动剂通过与不同的DA相互作用可能会产生各种行为效应受体亚型。该假设将通过确定针对不同DA受体的反义ODN的影响 DA激动剂介导的不同行为的亚型奎因螺旋。 DA受体mRNA将通过原位杂交评估组织化学，DA受体的密度和位置将是通过受体放射自显影评估。与 DA活动的改变也将与观察到的行为变化。最后，作为D3，D4或 D5 DA受体目前尚不清楚，ODN的影响朝着编码这些DA受体亚型编码的mRNA将是通过测量一系列行为来评估，再次将这些行为相关联随着DA受体及其mRNA的改变而改变。在所有这些研究，将格外小心，以确定是否实际上，观察到的生物行动是选择性的，它们是否是由于抑制了特定DA受体亚型的合成。例如，ODN的阳性和负面对照将是包括这些研究以及行为，生化和分子反义ODN的影响将进行详细检查，包括有关特定DA水平的时间和剂量反应研究受体mRNA和DA受体亚型的密度。我们期望这些研究不仅会提供有关新合成的DA受体池的功能作用，但会还提供了修改特定DA介导的事件的新策略在中枢神经系统中，可以为发现DA受体新发现的亚型的功能也许对于其他神经递质的受体功能系统。他们也可能有助于开发小说的基础治疗某些疾病（例如精神分裂症）的治疗剂与异常DA活性相关的迟发性运动障碍。