Differential changes in dopaminoceptive neurons during cocaine withdrawal

可卡因戒断期间多巴胺感受神经元的差异变化

• 批准号: 8061783
• 负责人: Alexandria Lynne Nugent
• 金额: $ 5.13万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8061783
• 关键词: Affect; Animal Model; Animals; Behavior; Behavioral; Brain; Brain region; C57BL/6 Mouse; Candidate Disease Gene; Cells; Chronic; Cocaine; Cocaine Dependence; Corpus striatum structure; Cues; Dopamine D1 Receptor; Dopamine D2 Receptor; Drug Addiction; Drug usage; Environment; Experimental Designs; Exposure to; Extinction (Psychology); Fluorescence-Activated Cell Sorting; Gene Expression; Genes; Hour; Incubated; Individual; Knowledge; Laboratories; Life; Mediating; Messenger RNA; Microarray Analysis; Molecular Profiling; Mus; Neurons; Nose; Nucleus Accumbens; Output; Pathway interactions; Pharmaceutical Preparations; Population; Protein Analysis; Proteins; Rattus; Recovery; Recurrence; Relapse; Reporter; Reporting; Research; Rewards; Saline; Schedule; Self Administration; Self-Administered; Signal Pathway; Societies; Sorting - Cell Movement; Sucrose; Testing; Time; Tissue-Specific Gene Expression; Training; Transgenic Mice; Treatment outcome; Western Blotting; Withdrawal; Work; addiction; base; cell type; cocaine exposure; cost; craving; drug craving; drug seeking behavior; drug withdrawal; experience; improved; insight; interest; learning extinction; mRNA Expression; mouse model; neuroadaptation; protein expression; response; treatment strategy

DESCRIPTION (provided by applicant Drug addiction is a devastating recurrent illness, which has substantial cost to both the individual and society. The transition from drug use to addiction is believed to be mediated by drug-induced alterations in neuronal intracellular signaling pathways and subsequent changes in gene expression. While many of these drug-induced alterations are transient, it is hypothesized that long-term alterations in gene expression must persist, which underlie long-term addiction-related behaviors such as craving and relapse. Activation of dopaminoceptive neurons in the nucleus accumbens (NAc), a brain region intricately involved in the rewarding and motivational aspects of drug addiction, has been shown to initiate a variety of neuronal, and ultimately, behavioral responses. For example, local activation of D1 or D2 dopamine receptors in the NAc has previously been shown to increase drug-seeking responses in withdrawal. Alternatively, brain-wide D1 receptor stimulation blocks both cocaine and cue-induced reinstatement. As cocaine addicted individuals frequently report that their recovery is hampered by increased craving for drug over time, the first aim of the proposed studies will be to determine if cocaine-seeking behaviors increase over extended periods of withdrawal in mice, similar to previous reports of "incubation" of cocaine seeking in rats. Demonstrating the incubation phenomenon in mice would allow the powerful use of transgenic mouse models in the study the neuroadaptations that coincide with incubation. Thus, the second aim of the proposed research will utilize fluorescence activated cell sorting (FACS) to obtain isolated populations of D1-containing or D2-containing neurons from the NAc of mice at withdrawal times that coincide with incubation of cocaine-seeking behavior. These isolated neuronal populations will be examined using microarray technology to identify differential changes in gene expression that persist or develop in D1 and D2 receptor-containing cell types from early to late cocaine withdrawal. Changes in mRNA and protein levels will be verified by qRT-PCR and Western blot, respectively. The final aim of this project will determine whether extinction of cocaine seeking alters these long- term changes in gene expression, or produces new changes induced specifically by extinction training experience in D1 and D2 cell types. These studies will allow us to identify differential neuroadaptations in the direct (D1) versus indirect (D2) ventral striatal output pathways, which could potentially contribute to a propensity for relapse, as well as determine the effect of extinction training on gene expression in these pathways as a potential treatment strategy to normalize or alter changes related to long-term withdrawal from chronic cocaine self-administration. PUBLIC HEALTH RELEVANCE: The proposed work will provide insights into the fundamental alterations that persist even into long-term withdrawal in the brain, which may contribute to increases in drug craving over time and an increased propensity toward relapse. Application of this knowledge may provide insights into new treatment strategies during drug withdrawal thereby decreasing the relapse rate and improving treatment outcomes.

药物成瘾是一种毁灭性的复发性疾病，对个人和社会都有巨大的成本。从药物使用到成瘾的转变被认为是由药物诱导的神经元细胞内信号通路的改变和随后的基因表达变化介导的。虽然许多药物诱导的改变是短暂的，但据推测，基因表达的长期改变必须持续存在，这是长期成瘾相关行为（如渴望和复发）的基础。多巴胺感受神经元在神经核（NAc），复杂地参与药物成瘾的奖励和动机方面的大脑区域，激活已被证明启动各种神经元，并最终，行为反应。例如，NAc中D1或D2多巴胺受体的局部激活先前已被证明会增加戒断时的药物寻求反应。或者，全脑D1受体刺激阻断可卡因和线索诱导的恢复。由于可卡因成瘾者经常报告说，随着时间的推移，他们的恢复受到对药物的渴望增加的阻碍，拟议研究的第一个目的将是确定在小鼠中，可卡因寻求行为是否会随着戒断时间的延长而增加，类似于之前关于大鼠可卡因寻求的“潜伏期”的报道。在小鼠中证明潜伏现象将使转基因小鼠模型在研究与潜伏相一致的神经适应中得到有力的利用。因此，所提出的研究的第二个目的将利用荧光激活细胞分选（FACS），以获得分离的群体D1-或D2-含有神经元的NAC小鼠在停药时间，符合可卡因寻求行为的孵化。将使用微阵列技术检查这些分离的神经元群体，以确定从早期到晚期可卡因戒断在含有D1和D2受体的细胞类型中持续或发展的基因表达的差异变化。mRNA和蛋白质水平的变化将分别通过qRT-PCR和Western印迹法进行验证。该项目的最终目的将确定可卡因寻求的消退是否改变了基因表达的这些长期变化，或产生由D1和D2细胞类型的消退训练经验特异性诱导的新变化。这些研究将使我们能够确定直接（D1）与间接（D2）腹侧纹状体输出通路中的差异神经适应，这可能有助于复发倾向，并确定灭绝训练对这些通路中基因表达的影响，作为一种潜在的治疗策略，以正常化或改变与长期戒断相关的变化。 公共卫生关系：拟议的工作将提供对大脑中甚至持续到长期戒断的根本改变的见解，这可能有助于随着时间的推移增加药物渴望和增加复发的倾向。这些知识的应用可以为停药期间的新治疗策略提供见解，从而降低复发率并改善治疗结果。