OPIATE AND ENDORPHIN EFFECTS ON CNS TISSUE CULTURES

阿片和内啡肽对中枢神经系统组织培养的影响

• 批准号: 3207085
• 负责人: STANLEY M CRAIN
• 金额: $ 15.42万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-07-01 至 1986-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3207085
• 关键词: action potentials; dorsal root; drug tolerance; electrophysiology; embryo /fetus tissue /cell culture; morphine; neuropharmacology; opiate alkaloid; organ culture; reflex; serotonin

Electrophysiologic analyses during chronic application of opioids to organotypic explants of fetal mouse spinal cord with attached dorsal root ganglia (DRGs) have provided the first demonstration that isolated mammalian CNS tissues can, in fact, develop a marked tolerance after several days' exposure in vitro.* Attempts will be made to clarify cellular mechanisms regulating development of tolerance and dependence in these unique CNS tissue cultures by introduction of specific metabolic and pharmacologic blocking agents and by other selective manipulations of the rigorously controlled physicochemical environment of these cultures. Extracellular recordings of the changes in DRG-evoked dorsal-horn network responses during chronic exposure to opioids will be correlated with intracellular recordings from the DRG neurons to detect possible functional alterations in presynaptic DRG terminals during development of tolerance, e.g. decreased opioid sensitivity, increased calcium conductance. Factors leading to the marked increase in opiate binding that occurs in our cord-DRG explants after chronic exposure to naloxone will be analyzed and similar methods will be used to detect possible changes in opiate receptor levels in tolerant cultures. Further studies of cross-tolerance between morphine and opioid peptides will be made to clarify the degree to which tolerance selective for receptor subtypes may develop in the dorsal-horn networks of cord-DRG explants. Development of cross-tolerance to the acute depressant effects of serotonin, and possibly to other monoamines, in opioid-tolerant cord-DRG explants will be analyzed with specific transmitter antagonists. Development of physiologic properties of opioid dorsal-horn networks and their DRG inputs will be studied in normal culture media and following chronic exposure to opioid agonists and antagonists introduced at early stages of maturation of fetal cord-DRG, and isolated DRG, explants in vitro. Correlative studies will be made with cord-DRG tissues explanted from pregnant rodents after chronic exposure to opioids in utero. The proposed studies should provide valuable insights into mechanisms of tolerance and plasticity in opioid systems of the CNS and to problems in maternal narcotic addiction. Crain et al., Life Sciences 25:1797-1802, 1979: 31:241-247, 1982.

慢性应用阿片类药物治疗脑缺血的电生理分析 带背根的胚胎小鼠脊髓器官型外植体 神经节（DRG）提供了第一个证明， 事实上，哺乳动物的CNS组织可以在 体外暴露数天。* 将努力澄清 调节耐受性和依赖性发展的细胞机制 这些独特的中枢神经系统组织培养物通过引入特定的代谢和 药理学阻断剂和其他选择性操作的药物， 严格控制这些培养物的理化环境。 背根节诱发背角神经网络变化的细胞外记录 长期暴露于阿片类药物期间的反应将与 DRG神经元的细胞内记录，以检测可能的功能 在耐受性发展过程中突触前DRG末端的改变， 例如阿片类药物敏感性降低，钙离子传导增加。 因素 导致在我们的大脑中， 将分析慢性暴露于纳洛酮后的脊髓背根神经节外植体， 类似的方法将用于检测阿片受体的可能变化 在宽容的文化中。 交叉耐受性的进一步研究 吗啡和阿片肽将澄清的程度， 对受体亚型的选择性耐受可能在背角形成， 脊髓背根神经节外植体网络。 对急性淋巴细胞白血病的交叉耐受性 5-羟色胺，可能还有其他单胺， 阿片类药物耐受性脊髓背根节外植体将用特定的 递质拮抗剂 阿片类药物生理特性的研究进展 背角网络及其背根神经节输入将在正常培养中进行研究 介质和慢性暴露于阿片激动剂和拮抗剂后 在胎儿索-DRG成熟的早期阶段引入，并分离 DRG，体外外植体。 将与cord-DRG进行相关研究 长期暴露于阿片类药物后妊娠啮齿动物的组织 在子宫里 拟议的研究应提供宝贵的见解， 中枢神经系统阿片系统的耐受性和可塑性机制， 产妇吸毒成瘾的问题。 Crain等人，生命科学25：1797-1802，1979：31：241-247，1982。