THE DEVELOPMENTAL NEUROCHEMISTRY OF METHADONE

美沙酮的发育神经化学

• 批准号: 3838703
• 负责人: SUSAN ROBINSON
• 金额: --
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3838703
• 关键词: acetylcholine; behavior test; brain metabolism; choline acetyltransferase; developmental neurobiology; drug addiction; drug delivery systems; drug withdrawal; embryo /fetus drug adverse effect; endogenous opioid; enkephalins; gas chromatography mass spectrometry; immunocytochemistry; laboratory rat; methadone; neurochemistry; neuropeptide receptor; neurotransmitter metabolism; newborn animals; opioid receptor; pregnancy; radioimmunoassay; receptor binding

This work will more thoroughly examine the neurochemical basis of the neurobehavioral abnormalities observed following prenatal exposure to opioids with a long-term goal of preventing or treating these deficits in children exposed to methadone prenatally. This project will continue work begun previously in this area and specifically will [1] determine whether neurochemical (i.e. changes in acetylcholine content and/or turnover) and behavioral (i.e. changes in acquisition of the negative geotaxic reflex and vertical screen performance and in tail-flick response to morphine) effects observed following prenatal exposure to methadone result from a direct action of methadone on the developing nervous system or rather from neonatal withdrawal; [2] determine whether neurochemical and behavioral effects following prenatal exposure to methadone and/or withdrawal are related to changes in brain regional endogenous opioids or opioid receptor binding; and [3] determine whether neonatal changes in brain regional acetylcholine (ACh) content observed in the above animals are related to changes in the number of cholinergic neurons or to changes in enzymatic activity. It is postulated that some of the observed neurochemical and behavioral changes observed after prenatal exposure may result from neonatal withdrawal whereas others may result from changes in endogenous opiate systems as a direct result of the action of methadone on the developing nervous system. Female rats will be implanted with a 28 day osmotic minipump containing water of methadone on day 8 of pregnancy. Neonatal withdrawal will be prevented by postnatal exposure to methadone via maternal milk. Pups will be cross-fostered to mothers who have been implanted with water or methadone pumps. The effect of this treatment will be determined on brain regional ACh and met- and leu-enkephalin content and mu-and delta-opioid receptor binding in weaning and adult rats. ACh turnover will be assessed by a mass fragmentographic technique that measures the relative incorporation of deuterium label from infused phosphorylcholine precursor into choline and ACh. Brain regional enkephalin and beta-endorphin content will be measured by the use of radioimmunoassay. Mu-Opioid and delta-opioid receptor binding will be determined in homogenates of relevant brain regions. Choline acetyltransferase (ChAT) activity will be assessed by a radioenzymatic assay and the number of the cholinergic neurons identified by immunohistochemical localization of ChAT. Behavioral testing will consist of measuring a standard array of developmental milestones and measuring the antinociceptive response to opioid manipulations in the tail-flick test. Once the effect of in utero methadone exposure on neurochemistry is more completely understood, efficacious therapeutic management can be developed for pregnant addicts, the neurobehavioral deficits exhibited by those exposed to methadone prenatally, and prevention of drug abuse in the children of addicts.

这项工作将更彻底地检查 产前暴露后观察到的神经行为异常 阿片类药物的长期目标是防止或治疗这些缺陷 儿童在产前暴露于美沙酮。 这个项目将继续工作 以前在该领域开始，特别是[1]确定是否是否 神经化学（即乙酰胆碱含量和/或周转的变化）和 行为（即负面地球反射的获取的变化和 垂直屏幕性能和对吗啡的尾部响应）效果 在产前暴露于美沙酮之后观察到直接导致的美沙酮 美沙酮对发育中的神经系统的作用，或者从 新生儿戒断； [2]确定神经化学和行为是否 产前暴露于美沙酮和/或戒断后的影响是 与大脑区域内源性阿片类药物或阿片类药物受体的变化有关 结合； [3]确定新生儿的大脑区域变化 在上述动物中观察到的乙酰胆碱（ACH）含量与 胆碱能神经元数量的变化或酶促变化 活动。 据推测，某些观察到的神经化学和 产前暴露后观察到的行为改变可能是由 新生儿戒断，而其他可能是由于内源性的变化而导致的 阿片类系统是美沙酮对 发展神经系统。 雌性大鼠将植入28天 怀孕第8天，渗透含有美沙酮的水。 新生儿戒断将通过产后暴露于美沙酮来预防 通过母乳。 幼崽将交叉送给那些曾经的母亲 用水或美沙酮泵植入。 这种治疗的影响将 确定大脑区域ACH，MET和LEU-ENKEPHALIN含量以及 在断奶和成年大鼠中结合的MU-and Delta-Apoid受体结合。 ach 营业额将通过质量片段学技术进行评估 测量注入的氘标签的相对掺入 磷酸胆碱前体进入胆碱和ACH。 大脑区域 Enkephalin和beta-endorphin含量将通过使用 放射免疫分子。 MU-阿片类和三角洲阿片受体结合将是 在相关大脑区域的匀浆中确定。 胆碱 乙酰基转移酶（CHAT）活性将通过放射酶进行评估 测定和胆碱能神经元的数量 聊天的免疫组织化学定位。 行为测试将组成 测量标准的发展里程碑并测量 在尾式测试中，对阿片类药物操纵的反感染反应。 一旦子宫美沙酮暴露对神经化学的影响就会更多 完全理解，有效的治疗管理 对于怀孕的瘾君子，那些人表现出的神经性缺陷 在产前暴露于美沙酮，并预防药物滥用 吸毒者的孩子。