Determining the effect of early resource scarcity on adolescent addiction-related behavior and cell-type specific transcription

项目摘要 早期生活经历可能对药物使用的风险和适应力产生长期影响 疾病（SUD）。虽然生命早期的创伤会增加SUD的风险，但短暂的早期应激源暴露可以促进 应力接种或后期恢复力。许多研究早期环境如何影响 成瘾相关的行为集中在成年动物的结果。然而，这种方法忽略了 经验改变了与SUD有关的大脑区域的发展轨迹，并限制了我们的能力， 知道SUD的干预措施是否会更早有效，例如在青春期，当第一次接触药物时， 虐待经常发生。这项提案解决了这一差距，并测试了一个短暂的早期资源稀缺的大鼠模型 改变青春期冲动，阿片类药物服用和内侧前额叶皮层细胞类型特异性转录 （mPFC），这是青少年时期发育的奖励回路的关键部分。该提案基于我们的实验室 广泛的工作特点的影响，有限的床上用品/筑巢（LBN）操纵成人成瘾- 相关成果。在黎巴嫩，母鼠和幼鼠在出生后第一周处于低资源环境中， 将其效果与在整个发育过程中用充足资源饲养的大鼠进行比较。我们之前发现， LBN导致成瘾相关行为的性别特异性弹性，减少冲动选择和吗啡 在成年雄性大鼠中，而不是在成年雌性大鼠中。我们还发现，在奖励中， 成年LBN男性中的回路，可以有助于恢复。本提案将扩大这项工作，以确定， 第一次，LBN是否会引起青春期大鼠类似的行为和分子变化。将使用目标1 创新的新行为程序，允许测试延迟折扣的冲动选择， 吗啡自我管理在青春期大鼠。我们希望，像成年人一样，LBN将促进男性特异性 对青少年冲动和吸毒的适应能力。Aim 2将建立在新的未发表的单核RNA上 使用scRNAseq技术评估LBN如何改变成人mPFC中的细胞类型特异性转录。这 这种方法克服了过去使用大块组织的工作的局限性，在大块组织中转录组学改变不能被 分配给任何特定的细胞类型。在成年人中，我们发现LBN改变了一种兴奋性神经元亚型的基因， 只有成年男性的mPFC中的多巴胺能神经元和这些基因中的几个参与了囊泡神经元的表达。 这可能导致突触前谷氨酸释放的改变。在这里，我们将测试预测，LBN 在青少年中引起类似的雄性特异性转录改变， 发现mPFC中基因定义的细胞亚型内的新基因表达变化。通过 结合这种新的青少年表型与以前的成人工作，我们可以确定LBN如何影响 成瘾相关行为的发展轨迹和mPFC的转录动力学。数据 这里产生的也将作为一个宝贵的资源，为领域的SUD和发展神经科学。

PROJECT SUMMARY Early life experiences can have long-lasting consequences on risk and resilience for developing substance use disorder (SUD). While trauma early in life increases risk for SUD, brief early stressor exposure can promote stress inoculation or later resilience. Much of the preclinical work studying how the early environment affects addiction-related behaviors has focused on outcomes in adult animals. However, this approach misses how early experiences alter the trajectory of the development of brain regions implicated in SUD and limits our ability to know if interventions for SUD would be effective earlier, such as in adolescence, when first exposure to drugs of abuse often occurs. This proposal addresses this gap and tests how a rat model of brief early resource scarcity alters adolescent impulsivity, opioid taking, and cell-type specific transcription in the medial prefrontal cortex (mPFC), a key part of the reward circuitry that is developing in adolescence. This proposal builds on our labs extensive work characterizing the effects of the limited bedding/nesting (LBN) manipulation on adult addiction- related outcomes. In LBN, dams and pups are in a low resource environment during pups first week of life and effects are compared to rats raised with adequate resources throughout development. We previously found that LBN causes sex-specific resilience to addiction-related behaviors, reducing impulsive choice and morphine taking, in adult male but not in adult female rats. We also found alterations in glutamatergic signaling in reward circuitry in adult LBN males that can contribute to resilience. This proposal will extend this work to determine, for the first time, whether LBN causes similar behavioral and molecular changes in adolescent rats. Aim 1 will used innovative new behavioral procedures that allow for testing impulsive choice with delayed discounting and morphine self-administration in adolescent rats. We expect that, like in adulthood, LBN will promote male-specific resilience to adolescent impulsivity and drug taking. Aim 2 will build on new unpublished single nucleus RNA sequencing (scRNAseq) assessing how LBN alters cell-type specific transcription in the adult mPFC. This approach overcomes limitations of past work using bulk tissue where transcriptomic alterations cannot be assigned to any particular cell type. In adults, we found that LBN alters genes in one subtype of excitatory glutamatergic neurons in the mPFC of only adult males and several of these genes are involved in vesicular transport, which could lead to altered presynaptic glutamate release. Here we will test the prediction that LBN causes similar male-specific transcriptional alterations in glutamatergic neurons in adolescents, while also discovering novel gene expression changes within genetically defined subtypes of cells in the mPFC. By combining this novel adolescent phenotyping with prior adult work, we can determine how LBN affects the developmental trajectory of addiction-related behaviors and the transcriptional dynamics of the mPFC. The data generated here will also serve as a valuable resource for the fields of SUD and developmental neuroscience.