Simulating Extinction Memory with Infralimbic DREADDs

使用下边缘 DREADD 模拟消退记忆

• 批准号: 8849885
• 负责人: JAMIE PETERS
• 金额: $ 17.58万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8849885
• 关键词: Accounting; Acetylcholine; Addictive Behavior; Adverse effects; Animal Model; Award; Behavior; Behavior Therapy; Behavioral Model; Blood - brain barrier anatomy; Brain; Brain region; CAV2 gene; Cholera Toxin; Clozapine; Cocaine; Cocaine Dependence; Cognitive Therapy; Data; Designer Drugs; Detection; Dorsal; Drug Addiction; Efferent Pathways; Electrodes; Engineering; Environment; Extinction (Psychology); FDA approved; Failure; Funding; GTP-Binding Proteins; Gene Transfer; Genes; Goals; Health; Human; Hypothalamic structure; Intervention; Knowledge; Laboratories; Lateral; Learning; Ligands; Mediating; Memory; Mentors; Modeling; Muscarinic Acetylcholine Receptor; Neurons; Nootropic Agents; Nucleus Accumbens; One-Step dentin bonding system; Oxides; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacological Treatment; Pharmacotherapy; Predisposition; Prefrontal Cortex; Procedures; Process; Proteins; Protocols documentation; Public Health; Rattus; Relapse; Research; Research Design; Research Personnel; Resistance; Retrieval; Rodent Model; Role; Science; Self Administration; Signal Transduction; Site; Staging; System; Techniques; Technology; Therapeutic Effect; Training; Vaccines; Viral; Viral Vector; Virus Diseases; Work; addiction; base; career; cognitive control; combinatorial; conditioned fear; craving; drug seeking behavior; implantation; insight; interest; neural circuit; neuromechanism; novel; novel strategies; preference; programs; protein expression; receptor; research study; skills; success; treatment strategy; vector

DESCRIPTION (provided by applicant): Cocaine addiction is a major health problem for which pharmacological treatments are lacking. Given the failure of many attempted pharmacotherapies and vaccines to reduce relapse, novel treatment strategies are needed. One limitation to standard therapies is that they must be systemically administered, and upon crossing the blood-brain barrier, they globally activate or inhibit neurons that express the receptor they target. Given that many receptors are ubiquitously expressed in different brain regions, our ability to couple this strategy with our existing knowledge of the neural circuitry of addiction is limited. Viral-mediated gene transfer strategies are bringing us one step closer in this effort, by allowing the restricted expression of specific genes in specific neurons. The advent of Designer Receptors Activated Exclusively by Designer Drugs (DREADDs) has brought us to the forefront of this effort. These synthetic receptors are modified muscarinic receptors that are fully functional in terms of their ability to activate G-protein signaling cascades, but have been engineered to no longer respond to their endogenous ligand, acetylcholine, and instead respond to the synthetic ligand, clozapine-N-oxide (CNO). Like standard pharmacotherapies, CNO can be administered systemically and crosses the blood-brain barrier to activate DREADDs. Viral-mediated transfer of DREADDs to specific neurons thus permits the specific targeting of pharmacotherapies to discrete neural circuit components, allowing us to use existing knowledge about addiction circuitry to control drug-seeking behavior. At this stage, the viral infection process is a neurosurgical one, but the process is no more invasive than the neurosurgical implantation of deep-brain stimulating (DBS) electrodes, a strategy which is currently being employed in treatment-resistant addicted patients. Nonetheless, once the viral vector has successfully infected neurons in the brain region of interest, it can be repeatedly activated or inactivated with systemic CNO, depending on the variety of DREADD chosen. For my dissertation work at MUSC, I discovered the infralimbic cortex to be a critical brain region for the inhibition of cocaine seeking (Peters et al., J Neurosi, 2008). This observation is related to the phenomenon of extinction, a procedure akin to cognitive behavioral therapy, which can be modeled in rats and is inversely related to relapse. Evidence suggests that the formation of an extinction memory involves recruitment of the infralimbic cortex to the addiction neural circuit, and when this circuit component is active, cocaine seeking is inhibited. If we take the infralimbic cortex offline using brain-site directed pharmacological inactivation, relapse occurs. Thus, constant activity in infralimbic cortex is necessary to suppress relapse. Unfortunately, extinction memory that is formed naturally through the process of behavioral therapy is relatively weak by comparison to the strong drug memories that drive relapse. Importantly, these drug reminders drive relapse through the prelimbic cortex, which lies just dorsal to the infralimbic cortex. This underscores the importance of therapies that can selectively target the ventral, infralimbic cortex to enhance extinction, without inadvertently promoting relapse through actions in its functional opponent, prelimbic cortex. The DREADD technology provides a way to do just that. My work in conditioned fear suggests that it is possible to pharmacologically simulate extinction memory by activating infralimbic cortex (Peters et al., Science, 2010). In this K01 proposal, I will attempt to elicit similar effects on cocaine seeking using the DREADD approach, which is especially advantageous for repeatedly stimulating infralimbic cortex. Very little is known about the efferent pathways by which infralimbic cortex controls extinction of addictive behaviors. The second aim of this proposal will couple the DREADD technology with a novel, retrogradely acting CAV2 viral vector, which will permit the exclusive expression of DREADDs in specific infralimbic pathways. I already have a strong hypothesis that the nucleus accumbens shell and lateral hypothalamus may account for these infralimbic-based therapeutic effects. However, the Fos expression analyses I propose will simultaneously permit a more open-ended approach to identifying other candidate regions. Identifying the efferent pathways by which infralimbic cortex inhibits cocaine seeking will allow for more focused interventions and potentially reduce side effects. My strong mentoring team will provide me with state-of-the-art training in the proposed techniques, and I will be immersed in an enriched institutional environment. The proposed research will: 1) identify a novel treatment strategy for addiction with strong translational potential, 2) further establish my current research niche in extinction of addictive memories, and 3) lay the groundwork upon which I can build an independent research program in the addiction field.

描述(申请人提供)：可卡因成瘾是一个主要的健康问题，缺乏药物治疗。鉴于许多尝试的药物疗法和疫苗都未能减少复发，因此需要新的治疗策略。标准疗法的一个限制是必须系统地给药，一旦越过血脑屏障，它们就会全局激活或抑制表达它们所针对的受体的神经元。鉴于许多受体在不同的大脑区域普遍表达，我们将这一策略与我们现有的神经回路知识相结合的能力 上瘾是有限的。病毒介导的基因转移策略允许在特定神经元中限制特定基因的表达，从而使我们在这一努力中更近了一步。由设计师药物(DREADD)专门激活的设计师受体的出现将我们带入了这一努力的前沿。这些合成受体是修饰的M受体，在激活G蛋白信号级联方面具有完全的功能，但已被设计为不再对其内源性配体乙酰胆碱产生反应，而是对合成配体氯氮平-N-氧化物(CNO)产生反应。与标准药物疗法一样，CNO可以全身给药，并跨越血脑屏障激活DREADDS。因此，病毒介导的DREADD到特定神经元的转移使药物治疗能够针对离散的神经回路组件，使我们能够利用现有的关于成瘾回路的知识来控制药物寻找行为。在这个阶段，病毒感染的过程是一个神经外科过程，但这个过程并不比深部脑刺激(DBS)电极的神经外科植入更具侵入性，这一策略目前正被用于治疗难治性成瘾患者。然而，一旦病毒载体成功地感染了感兴趣脑区的神经元，它就可以被全身性CNO反复激活或失活，这取决于所选择的DREADD的种类。在我在MUSC的论文工作中，我发现下缘皮质是抑制寻找可卡因的关键大脑区域(Peter等人，J Neurosi，2008)。这种观察与消亡现象有关，这是一种类似于认知行为疗法的过程，可以在大鼠身上建模，与复发成反比。有证据表明，消退记忆的形成涉及边缘下皮质向成瘾神经回路的招募，当该回路成分激活时，寻找可卡因的行为就会受到抑制。如果我们使用脑部位导向的药物失活使下缘皮质离线，就会复发。因此，下缘皮质的持续活动对于抑制复发是必要的。不幸的是，与导致复发的强大药物记忆相比，通过行为治疗过程自然形成的消退记忆相对较弱。重要的是，这些药物提醒通过位于下缘皮质背侧的大脑皮层推动复发。这就强调了 这些疗法可以选择性地针对腹侧边缘下皮质，以增强消退，而不会无意中通过其功能对手--前脑皮质的作用而促进复发。DREADD技术提供了一种实现这一点的方法。我在条件性恐惧方面的研究表明，通过激活下缘皮质，从药理上模拟消亡记忆是可能的(彼得斯等人，《科学》，2010年)。在这份K01提案中，我将尝试使用DREADD方法在寻求可卡因时产生类似的效果，这对反复刺激下缘皮质特别有利。关于传出的信息知之甚少 下缘皮质控制成瘾行为消退的途径。这项提议的第二个目的是将DREADD技术与一种新型的、逆行作用的CAV2病毒载体相结合，这将允许DREADD在特定的边缘下途径中独占表达。我已经有了一个强有力的假设，即伏隔核、壳核和下丘脑外侧可能解释了这些基于边缘以下的治疗效果。然而，我提出的Fos表达分析同时将允许一种更开放的方法来识别其他候选区域。确定下缘皮质抑制可卡因寻求的传出通路将允许进行更有针对性的干预，并可能减少副作用。我强大的指导团队将为我提供最先进的拟议技术培训，我将沉浸在一个丰富的机构环境中。这项拟议的研究将：1)确定一种具有很强翻译潜力的新的成瘾治疗策略；2)进一步建立我目前在成瘾记忆消亡方面的研究利基；3)为我在成瘾领域建立独立的研究计划奠定基础。