Impact of prenatal opioid exposure on long-range brain circuit connectivity and behavior

项目总结 2010年，据估计，美国有600万人滥用处方止痛药，引发 目前的阿片类药物流行。此外，据估计，美国有10%-20%的女性每人都会收到处方 怀孕期间服用阿片类药物，如羟考酮(Oxy)。总的来说，这导致了五倍的 在过去十年中，孕妇以及一个新生儿的处方药使用量有所增加 每15分钟戒断一次阿片，称为新生儿戒断综合征(NAS)。尽管快速增长的 出生时患有NAS的人群，关于产前接触阿片类药物的影响的基础研究工作 大脑发育，以及对终身行为的影响，还没有明确的定义。更好地识别以下因素的影响 产前接触氧对神经回路和行为发育的影响将为未来的研究奠定基础 深入到潜在的机制。长期目标是开发新的和创新的战略，以 缓解终身影响，目前对Oxy的关注特别是基于对以下方面的安全性感知 其FDA批准的状态。在子宫内暴露于Oxy的成年小鼠中进行的广泛的行为测试 表明这种发育性侮辱会产生与冲动控制和反应有关的行为缺陷 阿片类药物，具有性别特异性的影响，这与有关接触儿童的有限数据一致。 子宫内的阿片类药物。内侧前额叶皮质(MPFC)是支配这些区域的神经回路的核心成员。 行为，通常与纹状体和杏仁核驱动的额叶下部有关。因此，最重要的是 假说是，出生前Oxy改变了前额叶皮质长距离输入的发育，结果 行为失调症。为了开始解决这个问题，在中执行了无偏单突触电路跟踪 GAD2-CRE小鼠创建两性对mPFC抑制的所有直接、远程输入的全脑图 神经元。与额叶下垂的可能性一致，这一分析揭示了显著的和选择性的 女性杏仁基底外侧核(BLA)至mPFC中间神经元(INS)的结构连接增强 胎儿期暴露在氧气中。这导致了这里要解决的工作假说，即产前Oxy 暴露产生BLA介导的对mPFC的抑制，导致行为失调。完成 这两个拟议的AIMS有望产生以下结果：(1)单突触的无偏全脑图 产前对兴奋性和抑制性(PV，SST和VIP+)mPFC神经元的远程输入 氧暴露，以确定这些输入的来源和平衡。(2)确定《基本法》的影响力 在功能连接方面，使用高密度硅，在产前暴露于氧气后的mPFC 具有光遗传刺激和行为的探针，使用化学遗传学。这项拟议的研究预计将 为未来的机械研究提供一个框架，旨在进一步定义功能子电路，如何 最好地减轻产妇使用阿片类药物的后果，并评估当前NAS干预措施的影响 受雇于NICU，由出生后阿片类药物替代疗法组成。

PROJECT SUMMARY In 2010, an estimated 6 million individuals in the United States abused prescription pain relievers, triggering the current opioid epidemic. Further, an estimated 10-20% of women in the U.S. receive a prescription each year for an opioid, such as oxycodone (OXY), during pregnancy. Collectively, this has resulted in a five-fold increase in prescription drug use among expectant mothers over the last decade, as well as one baby born every 15 minutes in opioid withdrawal, termed neonatal abstinence syndrome (NAS). Despite a rapidly growing population of individuals born with NAS, basic research efforts on the effects of prenatal exposure to opioids on brain development, as well as the lifelong behavior impacts, are poorly defined. Better identifying the effects of prenatal OXY exposure on the development of neural circuits and behavior will allow for future investigations into the underlying mechanisms. The long-term goal is development of novel and innovative strategies to mitigate the lifelong impact and the current focus on OXY specifically is based on the perceived safety due to its FDA-approved status. A broad battery of behavioral tests performed in adult mice exposed to OXY in utero indicates this developmental insult produces behavioral deficits related to impulse control and response to opioids, with sex-specific effects, that are consistent with the limited data available on children exposed to opioids in utero. The medial prefrontal cortex (mPFC) is a core member of the neural circuitry governing these behaviors, often with a link to hypofrontality driven by the striatum and amygdala. Thus, the overarching hypothesis is that prenatal OXY alters the development of long-range inputs to the prefrontal cortex, resulting in behavioral dysregulation. To begin addressing this, unbiased monosynaptic circuit tracing was performed in GAD2-Cre mice to create whole brain maps in both sexes of all direct, long-range inputs to mPFC inhibitory neurons. Consistent with the possibility of hypofrontality, this analysis revealed a marked and selective elevation in structural connectivity to mPFC interneurons (INs) from the basolateral amygdala (BLA) in females exposed to prenatal OXY. This led to the working hypothesis to be addressed here, that prenatal OXY exposure produces BLA-mediated inhibition of the mPFC, resulting in behavioral dysregulation. Completion of the two proposed Aims is expected to produce the following: (1) Unbiased whole brain maps of monosynaptic long-range inputs to excitatory and inhibitory (PV, SST and VIP+) mPFC neurons in the context of prenatal OXY exposure, to determine the source and balance of these inputs. (2) Determination of the BLA’s influence over the mPFC following prenatal OXY exposure, in terms of functional connectivity, using high density silicon probes with optogenetic stimulation and behavior, using chemogenetics. The proposed research is expected to provide a framework for future mechanistic studies aimed at further defining the functional subcircuits, how to best mitigate the consequences of maternal opioid use and assessing the impact of current NAS interventions employed in NICUs, which consists of postnatal opioid replacement therapies.