Simulating Extinction Memory with Infralimbic DREADDs

使用下边缘 DREADD 模拟消退记忆

• 批准号: 8767607
• 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/8767607
• 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; Simulate; 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; public health relevance; 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（由申请人提供）：可卡因成瘾是一个主要的健康问题，目前缺乏药物治疗。鉴于许多尝试的药物疗法和疫苗未能减少复发，因此需要新的治疗策略。标准疗法的一个限制是它们必须全身给药，并且在穿过血脑屏障后，它们会全面激活或抑制表达其靶向受体的神经元。鉴于许多受体在不同的大脑区域中普遍表达，我们有能力将这种策略与我们对神经回路的现有知识结合起来 成瘾是有限的。病毒介导的基因转移策略通过允许特定神经元中特定基因的限制性表达，使我们在这一努力上更近了一步。设计药物独家激活的设计受体 (DREADD) 的出现使我们走在了这一努力的最前沿。这些合成受体是经过修饰的毒蕈碱受体，它们在激活 G 蛋白信号级联的能力方面具有完全功能，但经过工程改造，不再对其内源性配体乙酰胆碱做出反应，而是对合成配体氯氮平-N 做出反应-氧化物(CNO)。与标准药物疗法一样，CNO 可以全身给药并穿过血脑屏障激活 DREADD。因此，病毒介导的 DREADD 转移到特定神经元，使得药物治疗能够特异性靶向离散的神经回路成分，使我们能够利用有关成瘾回路的现有知识来控制药物寻求行为。在这一阶段，病毒感染过程是一种神经外科过程，但该过程并不比神经外科植入深部脑刺激（DBS）电极更具侵入性，这是一种目前用于难治性成瘾患者的策略。尽管如此，一旦病毒载体成功感染了感兴趣的大脑区域的神经元，它就可以被系统性 CNO 反复激活或灭活，具体取决于所选的 DREADD 种类。在 MUSC 的论文工作中，我发现边缘下皮层是抑制可卡因寻求的关键大脑区域（Peters 等人，J Neurosi，2008）。这一观察结果与灭绝现象有关，这是一种类似于认知行为疗法的过程，可以在大鼠中建模，并且与复发呈负相关。有证据表明，消退记忆的形成涉及将边缘下皮层募集到成瘾神经回路中，当该回路成分活跃时，可卡因的寻找就会受到抑制。如果我们使用大脑部位定向药理失活使边缘下皮质脱机，就会发生复发。因此，边缘下皮层的持续活动对于抑制复发是必要的。不幸的是，与导致复发的强烈药物记忆相比，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，这些药物提醒会通过边缘前皮层驱动复发，该皮层位于边缘下皮层的背侧。这强调了重要性 可以选择性地针对腹侧、边缘下皮层以增强消退的疗法，而不会无意中通过对其功能性对手边缘前皮层的作用而促进复发。 DREADD 技术提供了一种方法来做到这一点。我在条件性恐惧方面的研究表明，可以通过激活边缘下皮层来从药理学上模拟消退记忆（Peters et al., Science, 2010）。在这个 K01 提案中，我将尝试使用 DREADD 方法对可卡因寻求产生类似的影响，这对于反复刺激边缘下皮层特别有利。对于传出神经我们知之甚少 边缘下皮层控制成瘾行为消失的途径。该提案的第二个目标是将 DREADD 技术与一种新型的、逆行作用的 CAV2 病毒载体结合起来，这将允许 DREADD 在特定的边缘下途径中独家表达。我已经有一个强有力的假设，即伏隔核壳和下丘脑外侧可能解释了这些基于边缘下的治疗效果。然而，我建议的 Fos 表达分析将同时允许采用更开放的方法来识别其他候选区域。确定边缘下皮层抑制可卡因寻求的传出途径将允许更有针对性的干预措施并可能减少副作用。我强大的指导团队将为我提供有关拟议技术的最先进的培训，并且我将沉浸在丰富的机构环境中。拟议的研究将：1）确定一种具有强大转化潜力的新成瘾治疗策略，2）进一步确立我目前在成瘾记忆消除方面的研究定位，3）为我在成瘾记忆消除方面建立独立研究项目奠定基础。成瘾领域。