Serotonin receptors that potentiate addiction-related behavioral and molecular effects induced by methylphenidate plus SSRI exposure

项目概要/摘要： 许多人正在接触药物组合，包括哌醋甲酯（利他林）加上 选择性5-羟色胺再摄取抑制剂（SSRI）。这种药物组合适用于注意力缺陷 多动症（ADHD）/抑郁或焦虑共病（高达40%的儿童ADHD）和其他 精神疾病高剂量联合暴露也发生在例如滥用SSRI的患者中。 哌醋甲酯作为“认知增强剂”或派对药物。其中许多受试者是儿童或青少年。 这是一个公共卫生问题，因为潜在的长期行为和神经元的变化引起的， 这些精神药物。哌醋甲酯（一种多巴胺/去甲肾上腺素再摄取抑制剂），单独给药， 模仿可卡因的某些分子效应这些影响不那么强大，大概是因为 哌甲酯不影响血清素系统。事实上，申请人实验室的研究表明， SSRI联合哌醋甲酯治疗可增强滥用/成瘾相关行为， 基因调控，从而产生“可卡因样”的行为和分子特征。目前还不清楚是哪种血清素 受体亚型介导这些SSRI（5-羟色胺）效应。该项目的长期目标是更好地 了解血清素和多巴胺如何相互作用，以诱导其对药物成瘾相关行为的影响， 神经突起本申请的目的是确定血清素受体亚型和细胞类型 调节哌甲酯加SSRI组合对可卡因行为反应的影响， 青春期雄性和雌性大鼠纹状体和丘脑核的基因调控。中央 一种假说是SSRIs增强哌醋甲酯对可卡因诱导的行为和基因的影响 通过激活特定的5-羟色胺受体亚型进行调节。这一假设是基于初步数据 从申请人的实验室。拟议工作的基本原理是必须确定所涉及的 5-羟色胺受体亚型和神经元群体，以便为识别新的 药物干预可以避免这些影响。中心假设将通过追求三个测试 具体目的：1）确定哌甲酯+SSRI组合的行为和神经元后果 （氟西汀）治疗，比较临床相关剂量和“滥用剂量”; 2）确定血清素受体 有助于哌甲酯+SSRI对行为和基因调控的影响的亚型; 3）确定 大脑部位和细胞群调节这些行为和分子变化。对行为的影响将 使用可卡因诱导的位置偏好条件反射（CPP）和致敏模型来确定。 将通过原位杂交、RT-qPCR和Western印迹分析评估对基因调控的影响。 这些技术在我们的实验室中得到了很好的应用。这项研究意义重大，因为阐明 5-羟色胺增强精神兴奋剂诱导的行为和神经元变化的机制将 为未来开发新型抗抑郁药提供信息，以避免这些潜在的健康风险。

Project Summary/Abstract: Scores of people are being exposed to drug combinations that include methylphenidate (Ritalin) plus a selective serotonin reuptake inhibitor (SSRI). Such drug combinations are indicated for attention-deficit hyperactivity disorder (ADHD)/depression or anxiety comorbidity (in up to 40% of pediatric ADHD) and other psychiatric disorders. High-dose co-exposure also occurs, for example, in patients on SSRIs who abuse methylphenidate as a “cognitive enhancer” or party drug. Many of these subjects are children or adolescents. This is a public health concern because of potential long-term behavioral and neuronal changes induced by these psychotropic drugs. Methylphenidate (a dopamine/norepinephrine reuptake inhibitor), given alone, mimics some, but not other, molecular effects of cocaine. These effects are less robust presumably because methylphenidate does not affect serotonin systems. Indeed, research in the applicants' laboratories shows that treatment with an SSRI in conjunction with methylphenidate potentiates abuse/addiction-related behavior and gene regulation, thus producing “cocaine-like” behavioral and molecular profiles. It is unknown which serotonin receptor subtype(s) mediate these SSRI (serotonin) effects. The long-term goal of this project is to better understand how serotonin and dopamine interact to induce their effects on drug addiction-related behavior and neuronal processes. The objective of this application is to determine serotonin receptor subtypes and cell types that mediate the effects of methylphenidate plus SSRI combinations on behavioral responses to cocaine and gene regulation in striatum and nucleus accumbens in adolescent male and female rats. The central hypothesis is that SSRIs potentiate methylphenidate effects on both cocaine-induced behavior and gene regulation via activation of specific serotonin receptor subtypes. This hypothesis is based on preliminary data from the applicants' laboratories. The rationale for the proposed work is the necessity to determine the involved serotonin receptor subtypes and neuron populations, in order to lay the groundwork for identifying novel pharmacological interventions that avoid these effects. The central hypothesis will be tested by pursuing three specific aims: 1) Determine behavioral and neuronal consequences of combined methylphenidate+SSRI (fluoxetine) treatment, comparing clinically relevant doses and “abuse doses”; 2) Determine serotonin receptor subtypes that contribute to the methylphenidate+SSRI effects on behavior and gene regulation; 3) Determine brain sites and cell populations that mediate these behavioral and molecular changes. Effects on behavior will be determined using the cocaine-induced place preference conditioning (CPP) and sensitization models. Effects on gene regulation will be assessed by in situ hybridization, RT-qPCR, and Western blot analyses. These techniques are well-established in our labs. The proposed research is significant, because elucidating the mechanisms by which serotonin potentiates psychostimulant-induced behavioral and neuronal changes will inform the future development of novel antidepressants that avoid these potential health risks.