Calcium Imaging of Central Amygdala Activity after Fentanyl Escalation

芬太尼升级后中央杏仁核活动的钙成像

• 批准号: 10534346
• 负责人: Samantha Malone
• 金额: $ 4.68万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-03 至 2024-07-02
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10534346
• 关键词: Abstinence; Acute; Amygdaloid structure; Area; Automobile Driving; Behavior; Behavioral; Brain; Calcium; Cell Nucleus; Centers for Disease Control and Prevention (U.S.); Characteristics; Development; Dose; Emotional; Exposure to; Female; Fentanyl; Fluorescence; Frequencies; Future; Goals; Home; Hyperactivity; Image; Individual; Infusion procedures; Intake; Measures; Opioid; Oxycodone; Pattern; Pharmaceutical Preparations; Phase; Predisposition; Preparation; Rattus; Recording of previous events; Recovery; Relapse; Research; Rodent; Role; Saline; Self Administration; Severities; Slice; Sprague-Dawley Rats; Structure; Time; Withdrawal; Work; addiction; behavior influence; craving; experience; interest; male; neuromechanism; novel; novel therapeutic intervention; opioid use; opioid use disorder; overdose death; pre-clinical; relating to nervous system; response; treatment group; trend

Evidence suggests that rats given long access (LgA) sessions to self-administer (SA) opioids escalate their intake, while also showing greater withdrawal severity and drug-induced reinstatement compared to rats maintained on short access (ShA) daily SA sessions. Little is known about the neural changes that occur during contingent opioid escalation that may impact withdrawal and relapse. Past work examining opioid SA using ShA sessions in rodents has identified the central amygdala (CeA) as an area of interest that becomes hyperactive in acute withdrawal and may be involved in the incubation of craving that occurs after protracted withdrawal. However, these studies have not examined the impact of escalated opioid intake using LgA sessions on CeA activity during acute withdrawal, when individuals experience heightened craving and negative emotionality, or following protracted withdrawal during extended abstinence, when individuals experience an increased susceptibility to relapse. Furthermore, no study has determined if changes in CeA activity depend on the escalation of fentanyl intake that is self-administered contingently or merely from exposure to fentanyl per se, even if it were administered non-contingently. The specific aims of this research are to determine if contingent fentanyl escalation alters basal ex vivo CeA activity following either acute withdrawal (Aim 1) or protracted withdrawal (Aim 2). The effect of ex vivo application of fentanyl on the activity of CeA slices obtained following acute or protracted withdrawal will also be determined. Male and female Sprague Dawley rats will be divided into three groups: (1) contingent fentanyl, (2) yoked fentanyl, or (3) yoked saline. Rats in the contingent fentanyl group will undergo 7 days of fentanyl (2.5 ug/kg/inf) acquisition and 21 days of 6 h SA. Yoked rats will receive non-contingent infusions of fentanyl or saline dependent upon responding emitted by the contingent fentanyl rat. In preparation for calcium (Ca2+ ) imaging, rats will be euthanized either 17 h into withdrawal or after 30 days of forced abstinence. Ca2+ imaging will be conducted at baseline and in the presence of fentanyl (0.1 uM or 1 uM) to determine differences in CeA Ca2+ fluorescence, a measure of neural activity. We hypothesize that, at both stages of abstinence, fentanyl rats will demonstrate greater Ca2+ transients than yoked saline rats; contingent fentanyl rats may also display a greater effect than yoked fentanyl rats. We also hypothesize that, at both stages of abstinence, all rats will demonstrate a fentanyl, dose-dependent decrease in Ca2+ transients, an effect that will be greater in saline rats than fentanyl rats. Finally, we predict that greater basal CeA activity will be observed after protracted withdrawal compared to acute withdrawal, particularly for contingent fentanyl rats. Studying the mechanisms underlying differences in withdrawal and relapse after opioid escalation using Ca2+ imaging is highly novel and will elucidate the role of the CeA in driving withdrawal and relapse in OUD. The long-term goal of this work is to inform the development of novel treatments for OUD, particularly those that may target the CeA to reduce the negative emotionality and craving that occurs during acute withdrawal and throughout abstinence.

有证据表明，给予长期接触（LgA）自我给药（SA）阿片类药物的大鼠， 摄入，同时也显示出更大的戒断严重程度和药物诱导的恢复相比，大鼠 在短期访问（ShA）每日SA会话中维持。人们对在大脑皮层活动过程中发生的神经变化知之甚少。 可能影响戒断和复发的阿片类药物剂量增加。过去使用ShA检查阿片样物质SA的工作 在啮齿类动物中进行的一项研究已经确定中央杏仁核（CeA）是一个变得过度活跃的感兴趣区域 在急性戒断，并可能参与孵化的渴望，发生后，延长戒断。 然而，这些研究尚未检查使用LgA会话的阿片类药物摄入量增加对CeA的影响 急性戒断期间的活动，当个体经历强烈的渴望和负面情绪时，或 在长期禁欲期间长期戒断后，当个体经历增加的 易复发。此外，没有研究确定CeA活性的变化是否取决于 偶然或仅仅由于暴露于芬太尼本身而自我给药的芬太尼摄入量增加， 即使它是非偶然性的。这项研究的具体目的是确定是否有偶然性， 芬太尼递增改变急性戒断（Aim 1）或持续戒断后的基础离体CeA活性 退出（目标2）。体外应用芬太尼对以下获得的CeA切片活性的影响 急性或长期停药也将被确定。将雄性和雌性Sprague道利大鼠分开 分为三组：（1）应急芬太尼，（2）结合芬太尼，或（3）结合盐水。芬太尼特遣队中的老鼠 组将接受7天芬太尼（2.5 ug/kg/inf）采集和21天6 h SA。Yoked老鼠将收到 芬太尼或盐水的非偶然输注取决于偶然芬太尼大鼠发出的响应。 在准备钙（Ca 2+）成像时，将大鼠在停药后17小时或给药30天后安乐死。 强迫禁欲将在基线和芬太尼（0.1 uM或1 uM）存在下进行Ca 2+成像 以确定CeA Ca 2+荧光的差异，这是神经活动的量度。我们假设， 在戒断阶段，芬太尼大鼠将表现出比轭盐水大鼠更大的钙瞬变; 芬太尼大鼠也可能显示出比负轭芬太尼大鼠更大的效果。我们还假设在这两个阶段 所有大鼠在戒断后，将显示芬太尼在Ca 2+瞬变中的剂量依赖性降低，这种作用将 在盐水大鼠中比芬太尼大鼠中更大。最后，我们预测将观察到更大的基础CeA活性 与急性戒断相比，延长戒断后，特别是对于应急芬太尼大鼠。研究 使用Ca 2+成像的阿片类药物递增后戒断和复发差异的潜在机制是高度相关的。 新的，并将阐明的作用，CeA在驱动戒断和复发的OUD。长期目标是 工作是为OUD的新治疗方法的开发提供信息，特别是那些可能靶向CeA的治疗方法， 减少在急性戒断和整个禁欲期间出现的负面情绪和渴望。