Neurobehavioral mechanisms underlying xylazine and fentanyl co-use and withdrawal

项目摘要/摘要 处方和非法阿片类药物的使用已上升为公共健康危机，情况已转向芬太尼的使用。 鉴于芬太尼的效力是吗啡的100倍，使用它与更高的致死风险有关 服药过量。纳洛酮(纳尔康)逆转阿片类药物过量并加速戒断。然而，最近有报道称， 西拉津是一种麻醉剂，在意外的芬太尼过量死亡中越来越多地被检测到，这表明 成为一种非常受欢迎的掺假剂，可以延长芬太尼的“兴奋”和芬太尼的起效时间 戒断，以及在逆转过量用药时对纳洛酮的沉淀耐受。尽管如此，没有系统性的 到目前为止，研究已经评估了神经行为机制对这些影响的贡献。而阿片类药物 药理作用机制已经研究过，尚不清楚赛拉津如何加入芬太尼 抑制纳洛酮的作用，因为两者单独都没有这种作用。令人兴奋的是，我们可能已经发现 赛拉津联合芬太尼对纳洛酮耐药机制的研究进展 ART Pamgene PamStation技术，测量单个样本中数百个激酶的活性。我们展示了 伏隔核核心(NAcore)中高水平或低水平信号通路的初步数据 活性，这为我们提供了许多潜在的靶点来逆转纳洛酮耐药性和赛拉津对 芬太尼自主给药(SA)。我们假设赛拉津-芬太尼联合作用激活非- 减少消耗和延长芬太尼停药征兆的典型途径。我们的目标 这里是使用我们的Pamgene技术来揭示这些未知的机制，并确定这些影响 神经回路和行为。因此，我们将在以下目标中测试这些：1)确定赛拉津如何 影响芬太尼的效果，2)确定可行的治疗靶点以重新敏感芬太尼的戒断 在赛拉津-芬太尼SA升高后，以及3)确定改变NAcore和腹侧的神经回路 赛拉津-芬太尼SA升高后的被盖区(VTA)运动，如果这些运动是纳洛酮的基础 抵抗。我们将绘制赛拉津-芬太尼联合使用后NAcore和VTA的活性基因组图，并将 通过我们的广泛分析，我们发现的测试新的治疗目标发生了变化。我们将进一步测试这些 神经回路有助于共同使用诱导我们从Pamgene中识别的靶点的改变 分析，因此我们将确定抑制这些回路是否可以增强纳洛酮和 恢复因赛拉津-芬太尼联合使用而改变的神经靶点(通过动态组分析测量)。加在一起，这些 假说驱动的研究将显著增强我们对神经行为机制的理解 潜在的赛拉津-芬太尼多物质使用和戒断，并可能揭示新的治疗策略 用于逆转赛拉津-芬太尼诱导的纳洛酮无效。

PROJECT SUMMARY/ABSTRACT Prescription and illicit opioid use have risen to a public health crisis, with the landscape shifting to fentanyl use. Given that fentanyl is 100-fold more potent than morphine, its use is associated with a higher risk of fatal overdose. Naloxone (Narcan) reverses opioid overdose and precipitates withdrawal. However, recent reports indicate that xylazine, an anesthetic that is increasingly detected in accidental fentanyl overdose deaths, has become a highly sought-after adulterant that can prolong both the fentanyl “high” and the onset of fentanyl withdrawal, as well as precipitate resistance to naloxone in the reversal of overdose. Despite this, no systematic studies to date have evaluated the neurobehavioral mechanistic contributors to these effects. While opioid pharmacological mechanisms of action have been studied, it is not clear how the addition of xylazine to fentanyl inhibits the actions of naloxone, as either alone does not have this action. Excitingly, we have possibly discovered the mechanisms of how xylazine combined with fentanyl causes resistance to naloxone using our State-of-the- Art PamGene PamStation technology that measures hundreds of kinase activities in a single sample. We show preliminary data for the signaling pathways in the nucleus accumbens core (NAcore) that are hyper- or hypo- active, which gives us numerous potential targets for reversing naloxone resistance and xylazine’s effects on fentanyl self-administration (SA). We hypothesize that the xylazine-fentanyl combination activates non- canonical pathways that reduce consumption and prolong the onset of fentanyl withdrawal signs. Our objective here is to uncover these unknown mechanisms using our PamGene technology and determine how these impact neurocircuitry and behavior. Therefore, we will test these in our following Aims: 1) Determine how xylazine impacts the effects of fentanyl, 2) Determine viable therapeutic targets to resensitize fentanyl withdrawal following the escalation of xylazine-fentanyl SA, and 3) Determine neural circuits altering the NAcore and ventral tegmental area (VTA) kinomes following the escalation of xylazine-fentanyl SA and if these underlie naloxone resistance. We will map the active kinome of the NAcore and VTA following xylazine-fentanyl co-use and will test novel treatment targets that we find are changed via our extensive analysis. We will further test if these neural circuits contribute to co-use-induced alterations in targets that we have identified from our PamGene analysis, and thus we will determine if suppressing these circuits may enhance the actions of naloxone and restore neural targets altered by xylazine-fentanyl co-use (measured via kinome analysis). Together, these hypothesis-driven studies will markedly enhance our understanding of the neurobehavioral mechanisms underlying xylazine-fentanyl polysubstance use and withdrawal and will likely reveal novel treatment strategies for reversing the xylazine-fentanyl-induced naloxone inefficacy.