Estradiol signaling pathways mediating sex differences in striatal synaptic plasticity

物质使用障碍影响约15%的人口，在物质使用的所有阶段都存在性别差异。 女性性类固醇激素解释了一些差异，例如从偶然使用加速过渡到 成瘾，因为雌二醇在啮齿动物学习和可卡因自我管理中产生性别特异性差异。 长期使用可卡因会激活背侧纹状体回路。在这样的回路中，突触可塑性至关重要 对于各种类型的奖励学习，强调了这种可塑性在实质上可能发挥的潜在作用 使用障碍。因此，了解可卡因使用的性别差异需要确定雌二醇如何影响 背侧纹状体中的分子信号和突触可塑性。我们的初步结果显示雌二醇， 作用于雌二醇受体α，损害背内侧纹状体（DMS）的长时程增强（LTP）， 动情期雌性;然而，雌二醇作用的细胞类型尚未确定。纹状体棘突 神经元（SPN）是促进作用的直接途径SPN，或抑制作用的间接途径SPN。 行动，这些SPN的变化对各种行为后果至关重要。因此，必须 了解直接和间接途径SPN中的LTP缺陷。在本提案中，我们将检验假设 雌二醇损害DMS中间接途径SPNs中的LTP。背侧纹状体的LTP主要取决于 对细胞外调节激酶（ERK）的激活，也被可卡因和雌二醇修饰。 依普利酮增强可卡因介导的多巴胺释放并与代谢型谷氨酸受体相互作用 改变ERK激活，但需要一个公正的方法来确定雌二醇是否影响其他 信号通路我们的初步结果已经确定了几个信号通路， 然而，一个关键的问题是可卡因如何与雌二醇相互作用来调节这些信号传导 途径。我们提出了尖端的分子和转基因方法结合新的计算 建立模型来检验雌二醇介导的基因表达变化损害LTP的假设， 确定可卡因如何进一步改变突触可塑性的信号通路。具体目标 1，我们在转基因小鼠中进行电生理学检查，以确定在一个或多个细胞中雌二醇是否会损害LTP。 两个SPN。在具体目标2中，我们使用单核RNA测序，翻译， 核糖体亲和纯化，随后进行RNA测序和空间转录组学以鉴定信号传导 通过雌二醇和可卡因自身给药以细胞类型特异性和空间方式修饰的途径。在 具体目标3，我们使用创新的，数据驱动的信号通路建模，然后模型驱动 实验因果测试之间的相互作用的关键信号通路产生雌二醇介导的 LTP的缺陷。这项研究的成功完成将阐明雌二醇如何影响突触 可塑性的背侧纹状体，包括与可卡因，并提供了基础，为今后的工作， 了解奖励学习的性别差异和可卡因使用的后果。

Substance use disorders affect ~15% of the population, with gender differences in all stages of substance use. Female sex-steroid hormones explain some of the disparity, such as accelerated transition from casual use to addiction, as estradiol produces sex-specific differences in rodent learning and cocaine self-administration. Prolonged cocaine use is known to engage dorsal striatal circuits. Synaptic plasticity in such circuits is critical for a variety of types of reward learning, highlighting the potential role such plasticity could play in substance use disorders. Thus, understanding sex differences in cocaine use requires determining how estradiol impacts molecular signaling and synaptic plasticity in the dorsal striatum. Our preliminary results show that estradiol, acting at estradiol receptor type α, impairs long term potentiation (LTP) in dorsomedial striatum (DMS) in estrous females; however, the cell type in which estradiol acts has yet to be identified. Striatal spiny projection neurons (SPNs) are either direct pathway SPNs, which promote action, or indirect pathway SPNs, which inhibit action, and changes in these SPNs are critical for various behavioral consequences. Thus, it is essential to understand LTP deficits in both direct and indirect pathway SPNs. In this proposal, we will test the hypothesis that estradiol impairs LTP in indirect pathway SPNs in the DMS. LTP in the dorsal striatum critically depends on activation of extracellular regulated kinase (ERK), which also is modified by both cocaine and estradiol. Estradiol enhances cocaine-mediated dopamine release and interacts with metabotropic glutamate receptors to modify ERK activation, but an unbiased approach is needed to determine whether estradiol impacts other signaling pathways. Our preliminary results have identified several signaling pathways that are modified by estradiol; however, a critical question is how cocaine interacts with estradiol to modulate these signaling pathways. We propose cutting-edge molecular and transgenic approaches combined with novel computational modeling to test the hypothesis that estradiol-mediated changes in gene expression impair LTP and to determine how cocaine further modifies the signaling pathways underlying synaptic plasticity. In Specific Aim 1, we perform electrophysiology in transgenic mice to determine whether LTP is impaired by estradiol in one or both SPNs. In Specific Aim 2, we use innovative techniques of single nuclei RNA sequencing, translating ribosome affinity purification followed by RNA sequencing and spatial transcriptomics to identify signaling pathways modified by estradiol and cocaine self-administration in a cell-type specific and spatial manner. In Specific Aim 3, we use innovative, data-driven modeling of signaling pathways followed by model-driven experiments to causally test which interactions between critical signaling pathways produce estradiol-mediated deficits in LTP. Successful completion of the proposed research will delineate how estradiol influences synaptic plasticity in dorsal striatum, including in conjunction with cocaine, and provide a foundation for future work to understand sex differences in reward learning and the consequences of cocaine use.