Receptor variant-based changes in the role of PACAP in the nucleus accumbens during the transition to ethanol dependence

在向乙醇依赖过渡期间，伏隔核中 PACAP 的作用发生基于受体变异的变化

• 批准号: 10824968
• 负责人: Brody Allen Carpenter
• 金额: $ 4.77万
• 依托单位: DREXEL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10824968
• 关键词: Affect; Alcohol consumption; Alcohol dependence; Alcohols; Animals; Attention; Behavioral; Brain; Cannulas; Cells; Chronic; Consumption; Corticotropin-Releasing Hormone; Coupled; Data; Dependence; Development; Dynorphins; Ethanol; Ethanol dependence; Exhibits; GTP-Binding Proteins; Gene Expression; Genetic; Glutamates; Goals; Heavy Drinking; Individual; Injections; Intake; Limbic System; Measures; Microinjections; Modeling; Mus; Neurons; Neuropeptides; Nucleus Accumbens; Output; PACAP27; Pathway interactions; Peptides; Pharmacotherapy; Population; Process; Protein Isoforms; Publishing; RNA; Rattus; Receptor Gene; Recording of previous events; Role; Stress; Structure of paraventricular nucleus of thalamus; System; Testing; Time; Training; Up-Regulation; Variant; alcohol abuse therapy; alcohol exposure; alcohol use disorder; attenuation; behavioral response; binge drinking; combat; comparative; designer receptors exclusively activated by designer drugs; drinking; experimental study; knock-down; mRNA Expression; motivated behavior; neurochemistry; new therapeutic target; pituitary adenylate cyclase activating polypeptide; receptor; vapor

PROJECT SUMMARY Stress-related systems undergo a change during the transition to ethanol dependence, such that activation, which in a non-dependent state may leave unaffected or suppress intake, instead increases consumption. This effect reversal often coincides with an upregulation in receptor gene expression for stress-related neuropeptides; however, for the stress-related neuropeptide, pituitary adenylate cyclase-activating polypeptide (PACAP), the changes instead appear to occur via a specific increase in receptor variant expression. Our study focuses attention on the paraventricular nucleus of the thalamus (PVT), which has notably and selectively dense expression of the less ubiquitous PACAP peptide isoform, PACAP-27, where it is expressed in a subpopulation of glutamatergic neurons. In preliminary studies, we have found with a 20% ethanol intermittent access (IA) model of binge drinking, that effects of PACAP+ cell manipulation in the PVT can change based on drinking history. In PACAP-Cre mice drinking under the IA model for 6 weeks, Cre-dependent chemogenetic inhibition of PACAP+ cells stimulated ethanol drinking in low drinkers but instead inhibited intake in high drinkers. With preliminary evidence that these PACAP-27+ PVT neurons send dense projections to the nucleus accumbens (NAc), we have also found in rats, which drink lower levels of ethanol than mice, that those drinking under the IA model for 6 weeks respond to PACAP-27 injection into the NAc with a suppression of ethanol intake. Further, rats with a longer IA drinking history (10 weeks) show a specific increase in gene expression in the NAc of the HOP variant of the PACAP receptor (PAC1). We have confirmed with quantitative real-time (qRT-)PCR that the HOP and SHORT variants are present in the NAc of mice. Building on our preliminary and published data, we hypothesize that activation of PACAP-27+ cells that send afferents from the PVT to the NAc suppresses non- dependent, binge-like ethanol intake, but increases intake in a dependent state (Aim 1); and this shift in behavioral output occurs as the PACAP system becomes dysregulated resulting in a specific increase in PAC1 HOP receptor variant expression (Aim 2). To test this, Aim 1 investigates the effect of activation and inhibition of the PVT→NAc PACAP pathway on ethanol intake before and after dependence, by using PACAP-Cre mice and Cre-dependent excitatory and inhibitory DREADDs injected into the PVT paired with cannula guided microinjections of CNO into the NAc shell. To determine the involvement of PAC1 receptor variants in the NAc on ethanol intake, Aim 2 will measure PAC1 variant mRNA expression in the NAc of non-dependent and ethanol dependent mice and also use specific interfering (si)RNA to knock down the PAC1 receptor variants in the NAc of non-dependent and dependent mice. Together, these Aims will determine how the PACAP+ PVT→NAc pathway affects ethanol drinking across states and how PAC1 variant populations in the NAc are changed with the transition to dependence and, in turn, affect ethanol intake.

项目摘要 应激相关系统在向乙醇依赖性过渡期间经历变化，使得激活， 在非依赖性状态下，它可能不受影响或抑制摄入，而是增加消费。这 效应逆转通常与应激相关神经肽受体基因表达的上调相一致; 然而，对于应激相关的神经肽，垂体腺苷酸环化酶激活多肽（PACAP）， 相反，变化似乎通过受体变体表达的特异性增加而发生。我们的研究重点 注意丘脑室旁核（PVT），它具有显著的和选择性的致密 表达不太普遍的PACAP肽同种型PACAP-27，其中它在亚群中表达 的神经元。在初步研究中，我们发现，与20%的乙醇间歇性访问（IA） 酗酒模型，在PVT中PACAP+细胞操作的效果可以根据饮酒而改变 历史在PACAP-Cre小鼠中，在IA模型下饮用6周，Cre依赖的化学发生抑制 PACAP+细胞刺激低饮酒者的乙醇饮用，但抑制高饮酒者的摄入。与 初步证据表明，这些PACAP-27+ PVT神经元发送密集的投射到延髓核 (NAc)，我们还发现，在大鼠中，饮酒水平低于小鼠， 6周的IA模型对NAc中注射PACAP-27有反应，同时抑制乙醇摄入。此外，本发明还 具有较长IA饮酒史（10周）的大鼠显示出NAc中基因表达的特异性增加， PACAP受体（PAC 1）的HOP变体。我们已经用定量实时（qRT-）PCR证实， HOP和SHORT变体存在于小鼠的NAc中。根据我们的初步和公布的数据，我们 假设从PVT向NAc发送传入的PACAP-27+细胞的激活抑制了非- 依赖性的，暴食式的乙醇摄入，但在依赖状态下增加摄入量（目标1）; 当PACAP系统变得失调，导致PAC 1特异性增加时， HOP受体变体表达（目的2）。为了验证这一点，目标1研究了激活和抑制的效果 通过使用PACAP-Cre小鼠，观察PVT→NAc PACAP通路对酒精摄入依赖前后的影响。 和Cre依赖性兴奋性和抑制性DREADD注射到PVT中，与套管引导配对 将CNO显微注射到NAc壳中。为了确定PAC 1受体变体在NAc中的参与， 在酒精摄入量，目的2将测量PAC 1变体mRNA表达在NAc的非依赖性和乙醇 依赖小鼠，并使用特异性干扰（si）RNA敲低NAc中的PAC 1受体变体 非依赖性和依赖性的小鼠。这些目标将共同决定PACAP+ PVT→NAc 途径影响各州的乙醇饮用以及NAc中的PAC 1变异群体如何随着 过渡到依赖性，反过来又影响乙醇的摄入量。