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

项目总结 早期生活经历可能会对药物使用的风险和复原力产生长期影响 精神障碍(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能会促进 应激接种或后来的恢复能力。研究早期环境如何影响的大部分临床前工作 与成瘾相关的行为主要集中在成年动物的结果上。然而，这种方法错过了多早 经历改变了与SUD有关的大脑区域的发展轨迹，并限制了我们的能力 了解对SUD的干预是否会在更早的时候有效，例如在青春期，当第一次接触药物时 虐待行为时有发生。这项建议解决了这一差距，并测试了短暂的早期资源稀缺的老鼠模型 改变青少年冲动、阿片类药物摄取和内侧前额叶皮质细胞类型特异性转录 (MPFC)，这是青春期发育的奖励回路的关键部分。这项建议是以我们的实验室为基础的 大量的工作表征了有限的床上用品/巢(LBN)操作对成人成瘾的影响- 相关结果。在LBN，在幼崽出生的第一周和第二周，母羊和幼崽处于资源匮乏的环境中 效果被比作在整个发育过程中用足够的资源饲养的老鼠。我们之前发现， LBN导致特定性别对与成瘾相关的行为的弹性，减少冲动选择和吗啡 成年雄性大鼠服用，成年雌性大鼠不服用。我们还发现奖赏中谷氨酸能信号的变化 成年LBN男性体内有助于恢复能力的回路。这项提案将扩展这项工作，以确定 第一次，LBN是否会导致青春期大鼠类似的行为和分子变化。目标1将使用 创新的新行为程序，允许测试延迟折扣和冲动选择 青春期大鼠的吗啡自我给药。我们预计，就像在成年时期一样，LBN将促进男性特有的 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的基础上 测序(ScRNAseq)评估LBN如何改变成年mPFC的细胞类型特异性转录。这 这种方法克服了过去使用大量组织的工作的局限性，在这些组织中，转录改变是不可能的 分配给任何特定单元格类型。在成人中，我们发现LBN改变了兴奋性基因的一个亚型 只有成年男性mPFC中的谷氨酸能神经元和其中几个基因参与囊泡 运输，这可能导致突触前谷氨酸释放改变。在这里，我们将检验LBN的预测 在青少年中引起类似的男性特有的谷氨酸能神经元转录变化，同时也 在mPFC的遗传定义的细胞亚型中发现新的基因表达变化。通过 结合这种新的青少年表型和以前的成人工作，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 在这里产生的数据也将成为可持续发展和发展神经科学领域的宝贵资源。

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.