The role of the prelimbic area in compulsive drug seeking

前边缘区在强迫性药物寻求中的作用

• 批准号: 8553305
• 负责人: ANTONELLO BONCI
• 金额: $ 29.77万
• 依托单位: NATIONAL INSTITUTE ON DRUG ABUSE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8553305
• 关键词: Addictive Behavior; Area; Behavior; Brain; Cells; Cocaine; Conflict (Psychology); Consumption; Data; Decision Making; Dependovirus; Development; Drug Addiction; Drug usage; Economics; Electrophysiology (science); Functional disorder; Future; Glutamates; Goals; Halorhodopsins; Heart; Impairment; In Vitro; Individual; Ion Channel; Learning; Mediating; Modeling; Molecular; Neurons; Obsessive compulsive behavior; Outcome; Output; Pathway interactions; Pharmaceutical Preparations; Prefrontal Cortex; Probability; Process; Property; Punishment; Rattus; Recording of previous events; Research; Rewards; Role; Self Administration; Shock; Slice; Staging; Synapses; Time; Training; addiction; base; cost; drug seeking behavior; effective therapy; foot; gamma-Aminobutyric Acid; in vivo; interest; longitudinal analysis; neural circuit; neuroadaptation; novel; optogenetics; patch clamp; programs; receptor; relating to nervous system; research study; response; social; synaptic function

Current and future research Prelimbic stimulation in addicted rats decreases compulsive cocaine-seeking behavior. A hallmark of addiction is continued use of drugs despite negative consequences. This compulsive drug-seeking behavior is thought to result, in part, from drug-induced hypofunction in cortical regions, including the PFC. Because the PFC has critical function in exerting control over unwanted behaviors2, dysfunctions in this area may render an addict incapable of resisting the urge to seek drugs. Consistent with this hypothesis, my on-going research has uncovered significant decreases in neuronal activity in the PL in rats with a long history of cocaine self-administration. Moreover, in Addicted rats, photo-stimulation of channelrhodopsin (ChR2)-expressing PL neurons during self-administration sessions significantly reduced cocaine-seeking behaviors, but only after the rats have learned that lever pressing for cocaine is associated with foot shocks. Prior to the pairing of foot shocks with cocaine, photo-stimulation of ChR2-expressing PL neurons has no effect on cocaine-seeking behavior. The PL has been shown to guide goal-directed behaviors and in the absence of any punishment, the goal of the rat is to seek cocaine. Therefore the rat does not need to evaluate the outcome of the decision and activation of the PL has no effect. However, when future cocaine rewards are paired with punishments, a rat is faced with two conflicting goals, to get cocaine or to avoid shocks. In these situations, the rat must evaluate the value of cocaine against foot shocks. My data suggests that in the face of foot shocks, decreased PL activity biases the rats behavior towards continued cocaine seeking (Kourrich et al, under revision for Cell.) My future research program will examine two major PL circuits that may be altered by long-term voluntary consumption of cocaine to allow the execution of addictive behaviors. I will focus on the PL-BLA and the PL-NAc circuit. The PL-BLA and the PL-NAc projections are implicated in promoting goal-directed and drug-seeking behaviors3,7, but their role in regulating compulsive behaviors remains poorly understood. To examine the effects of cocaine-induced neuroadaptations in these two PL output pathways and identify their function in compulsive cocaine seeking, the following experiments will be performed: In vivo and in vitro patch-clamp recording in neurons from Addicted and Non-addicted rats. To identify cocaine-induced changes in the function of PL circuits and the underlying cellular mechanisms, in vivo and in vitro whole-cell patch clamp recordings will be made in Addicted and Non-addicted rats. Of particular interests are adaptations present in Addicted but not Non-addicted rats, which may uniquely permit compulsive cocaine seeking. In vivo patch-clamp recordings will be performed to examine the intrinsic electrophysiological properties of PL neurons in the context of a fully connected network. In addition, because the loss of inhibitory control in Addicted rats may reflect impaired PL responses to punishment, synaptic responses of PL neurons to foot-shocks will also be examined. Lastly, in vivo recordings will be made at various stages of self-administration training. This will provide a longitudinal analysis of cocaine-induced neuroadaptations at various stages of the addiction process. Changes in cocaine-induced network function can be mediated by molecular changes at the cellular and synaptic level. Among the possible neuroadaptations include function and or number of receptors and ion channels as well as release probability of transmitters (i.e. glutamate and GABA). To precisely analyze these parameters in Addicted and Non-addicted rats, in vitro patch-clamp recording in brain slices containing PL, BLA, and NAc will be made. In addition, I will use ChR2 to selectively examine changes in the excitatory strengths of projections from the PL- to BLA or NAc in the two groups. Together, in vivo and in vitro electrophysiological experiments will provide a thorough analysis of cocaine-induced changes at both the circuit and the cellular level. The identification of differences between Addicted and Non-addicted rats may reveal critical adaptations that facilitate compulsive, cocaine-seeking behavior. Optogenetic control of PL circuits to decrease compulsive cocaine seeking. I show that hypofunction of the PL has a critical role in permitting compulsive cocaine-seeking behaviors and that this behavior can be reversed with photo-activation of PL neurons. To understand the function of PL-BLA and PL-NAc circuits in compulsive cocaine seeking, I will use optogenetics to investigate afferent-specific excitatory synaptic function in the BLA or NAc in exerting inhibitory control over cocaine seeking. I will transduce PL projection neurons with adeno-associated virus encoding either ChR2 or halorhodopsin (NpHR) to stimulate or inhibit, respectively, afferent-specific neural activity in the BLA or NAc. Results from in vitro slice experiments will guide in vivo optogenetic experiments. For example, if the strength of a particular PL circuit is significantly reduced in the Addicted rats, ChR2 will be employed to selectively enhance these glutamatergic projections during cocaine seeking. In contrast, if an increase in synaptic strength in one or both of these circuits is observed, NpHR will be used to decrease its activity during cocaine seeking. Real-time modulation of neuronal circuits with optogenetics will establish a causal relationship between PL-circuits and its role in regulating compulsive behavior. Summary The loss of inhibitory control, despite knowing the negative consequences of this behavior, lies at the heart of compulsive drug use and addiction. My research seeks to identify cocaine-induced neuroadaptations, starting from individual synapses to progressing to specific neuronal circuits that contribute to decision-making impairments and allow maladaptive, compulsive cocaine seeking. The integration of rat addiction model with in vivo and in vitro electrophysiology and optogenetic targeting of specific cortical circuits provides the ideal platform to identify neural circuits and cellular mechanisms underlying addictive behaviors.

当前和未来的研究 对成瘾大鼠进行边缘前刺激可减少强迫性寻求可卡因的行为。 成瘾的一个标志是不顾负面后果继续使用毒品。这种强迫性的药物寻求行为被认为部分是由于药物引起的皮质区域（包括前额皮质）功能减退所致。 由于前额皮质在控制不良行为方面具有关键功能2，因此该区域的功能障碍可能会使成瘾者无法抵制寻求毒品的冲动。 与这一假设相一致的是，我正在进行的研究发现，长期自我服用可卡因的大鼠的 PL 神经元活动显着降低。 此外，在成瘾的大鼠中，在自我给药期间对表达通道视紫红质（ChR2）的 PL 神经元进行光刺激显着减少了可卡因寻求行为，但前提是大鼠已经知道按压杠杆获取可卡因与足部电击有关。 在足部电击与可卡因配对之前，表达 ChR2 的 PL 神经元的光刺激对可卡因寻求行为没有影响。 PL 已被证明可以指导目标导向的行为，并且在没有任何惩罚的情况下，老鼠的目标是寻找可卡因。 因此，大鼠不需要评估决策的结果，并且 PL 的激活没有影响。 然而，当未来的可卡因奖励与惩罚相结合时，老鼠面临着两个相互冲突的目标：获取可卡因或避免电击。 在这些情况下，大鼠必须评估可卡因对抗足部电击的价值。 我的数据表明，面对足部冲击，PL 活性降低会使大鼠的行为偏向于继续寻找可卡因（Kourrich 等人，正在为 Cell 进行修订。） 我未来的研究计划将检查两个主要的 PL 回路，这些回路可能会因长期自愿消费可卡因而改变，从而允许执行成瘾行为。 我将重点介绍 PL-BLA 和 PL-NAc 电路。 PL-BLA 和 PL-NAc 预测与促进目标导向和药物寻求行为有关 3,7，但它们在调节强迫行为中的作用仍然知之甚少。 为了检查可卡因诱导的神经适应对这两个 PL 输出途径的影响并确定它们在强迫性可卡因寻求中的功能，将进行以下实验： 成瘾和非成瘾大鼠神经元的体内和体外膜片钳记录。 为了确定可卡因诱导的 PL 回路功能和潜在细胞机制的变化，将对成瘾和非成瘾大鼠进行体内和体外全细胞膜片钳记录。 特别令人感兴趣的是成瘾大鼠而非非成瘾大鼠中存在的适应性，这可能独特地允许强迫性地寻求可卡因。 将进行体内膜片钳记录，以检查完全连接的网络背景下 PL 神经元的内在电生理特性。 此外，由于成瘾大鼠抑制控制的丧失可能反映了 PL 对惩罚的反应受损，因此还将检查 PL 神经元对足部电击的突触反应。 最后，将在自我管理训练的各个阶段进行体内记录。 这将对成瘾过程各个阶段可卡因诱导的神经适应进行纵向分析。 可卡因诱导的网络功能的变化可以通过细胞和突触水平的分子变化来介导。可能的神经适应包括受体和离子通道的功能和/或数量以及递质（即谷氨酸和 GABA）的释放概率。 为了精确分析成瘾和非成瘾大鼠的这些参数，将对含有 PL、BLA 和 NAc 的脑切片进行体外膜片钳记录。此外，我将使用 ChR2 选择性地检查两组中从 PL- 到 BLA 或 NAc 的兴奋强度的变化。 体内和体外电生理学实验将共同对可卡因引起的电路和细胞水平的变化进行彻底分析。 鉴定成瘾和非成瘾大鼠之间的差异可能会揭示促进强迫性、可卡因寻求行为的关键适应。 PL 电路的光遗传学控制可减少对可卡因的强迫性寻找。 我发现 PL 功能减退在允许强迫性寻求可卡因行为方面发挥着关键作用，并且这种行为可以通过 PL 神经元的光激活来逆转。 为了了解 PL-BLA 和 PL-NAc 回路在强迫性可卡因寻求中的功能，我将使用光遗传学来研究 BLA 或 NAc 中的传入特异性兴奋性突触功能对可卡因寻求施加抑制控制。 我将用编码 ChR2 或盐视紫红质 (NpHR) 的腺相关病毒转导 PL 投射神经元，以分别刺激或抑制 BLA 或 NAc 中的传入特异性神经活动。 体外切片实验的结果将指导体内光遗传学实验。 例如，如果成瘾大鼠中特定 PL 回路的强度显着降低，ChR2 将在寻找可卡因期间选择性地增强这些谷氨酸能投射。 相反，如果观察到这些回路中的一个或两个中的突触强度增加，则 NpHR 将用于减少可卡因寻找过程中的活动。 利用光遗传学实时调节神经元回路将建立 PL 回路及其在调节强迫行为中的作用之间的因果关系。 概括 尽管知道这种行为的负面后果，但抑制控制的丧失却是强迫性吸毒和成瘾的核心。我的研究旨在识别可卡因引起的神经适应，从单个突触开始，发展到导致决策障碍并导致适应不良、强迫性寻求可卡因的特定神经元回路。 大鼠成瘾模型与体内和体外电生理学以及特定皮层回路的光遗传学靶向相结合，为识别成瘾行为背后的神经回路和细胞机制提供了理想的平台。