Structural and molecular identification of circuitry underlying joint processing of motivation and aversion

摘要 物质使用障碍的一个核心标准是继续使用奖励物质，尽管有明确的 这些后果在其他情况下会非常令人厌恶，因此在驾驶回避方面具有强大的行为能力： 有害的身体后遗症、负面的社会影响和/或将用户置于危险境地。现代 吸毒成瘾模型援引了许多可能的正强化和负强化来源，但事实并非如此 已知哪个特定电路实际上在允许引起正常厌恶的动作中起作用（因果关系） 身体伤害，从生物体生存机制的角度来看，还没有完全理解 物质使用的破坏性后果可能完全无法阻止吸毒行为。 这种令人瞩目的厌恶的条件性，对药物滥用至关重要，在非药物滥用中也具有根本意义。 与药物有关的行为;正常厌恶的经历可以表现为改变（中性，甚至是积极的） 由于各种适应性和适应不良的原因，在某些情况下，这些影响可能被理解为 相对简单的神经经济学风险/收益或收益/损失考虑;例如，足够的奖励（例如， 大量食物/水资源的罕见递送）可以自适应地驱动对同类厌恶事件（例如， 暂时失去食物/水）。我们和其他人已经广泛地研究和描述了这些电路计算， 包括在目前赠款的支持的前期，通过精心建设仔细平衡， 限定值，同类奖励/厌恶刺激。然而，实现这一点的电路似乎 简单的适应行为（其中经历了奖励和厌恶的后果，但 期望值1只是更大的幅度）可能对于大多数 自然主义的情况下，其中奖励和厌恶是完全不同的。 在这个建议中，我们建立在我们对休闲，细胞特异性奖励电路的见解，利用下一代 电路询问技术，以识别（在全脑范围内）结构和分子定义的 在奖赏和厌恶的交叉点上的电路元件，脊椎动物的大脑通过它改变行为 对厌恶刺激的反应在目标1中，我们开发了适应这些范例的下一代兼容性，以获得 全脑布线和分子识别的所有细胞，特别是招募（活跃）在这个关键 行为（所有这些都记录在厌恶期间收集的遗传编码的Ca 2+传感器衍生的活动数据中， 抑制行为）。在目标2中，使用目标1的工具与我们最新的光遗传学控制相结合， 方法，我们将测试具体的电路活动假设的因果关系，在实施跨类别 厌恶的调节除了新颖的电路目标，将出现从全脑无偏见的 目标1的调查，我们已经有具体的电路级假设测试基于我们现有的 初步数据，确保提案的后续目标建立在已经坚实的基础上。我们 假设该候选电路活动（在从mPFC到特定 皮层下结构）通过破坏内部结构， 厌恶刺激的表征（和体验）。在目标3中，以我们的身份为基础（并以之为指导）， 自然地和因果地参与抑制厌恶反应的电路元件，在这个目的中，我们 在行为期间实现单细胞实时分辨率。在目标1和目标2的光纤读出策略中， 动态作为来自光纤的单个时间序列出现;尽管这些数据很有价值，但信号可能 增加可能是由于该地区活动的同步性改变或扩散，而不是由于活动的增加 在特定的靶神经元子集中。单细胞分辨率在因果牵连合奏这里不仅将 解决了这个基本问题，而且还允许对因果相关的特定细胞进行深入的分子分析， 具有明确的基本和翻译含义。 识别这种回路不仅可以深入了解奖励和厌恶的基础科学， 推进潜在的革命性的理解和目标的电路元件，可能是因果关系（或 治疗性）用于人类物质使用和神经精神障碍。

Abstract A core criterion of substance use disorder is continuing use of the rewarding substance despite clear consequences that would otherwise be highly aversive and thus behaviorally powerful in driving avoidance: harmful physical sequelae, negative social effects, and/or placement of the user in dangerous situations. Modern models of drug addiction invoke many possible sources of positive and negative reinforcement, but it is not known which specific circuitry is actually operative (causal) in allowing actions that cause normally-aversive physical harm, and it is not fully understood from the perspective of organismal-survival mechanisms how the destructive consequences of substance use could become entirely unable to deter drug use behavior. This remarkable conditionality of aversion, central to drug abuse, is also of fundamental significance in non- drug-related behavior; normally-aversive experiences can manifest with altered (neutral, or even positive) valence for a variety of adaptive and maladaptive reasons. In some cases, these effects might be understood by relatively simple neuroeconomic risk/benefit or gain/loss considerations; for example, sufficient reward (e.g. rare delivery of large food/water resources) may adaptively drive tolerance of same-class aversive events (e.g. temporary loss of food/water). We and others have studied and described these circuit computations extensively, including in the prior period of support from the present grant, by meticulous construction of carefully-balanced, defined-value, same-category reward/aversion stimuli. However, circuitry implementing this seemingly straightforward adaptive behavior (in which rewarding and aversive consequences are experienced, but expected-value of one is simply of greater magnitude) may be of insufficient complexity for the large majority of naturalistic situations, wherein reward and aversion are categorically different. In this proposal, we build upon our insights into casual, cell-specific reward circuitry, leveraging next-generation circuit-interrogation technology to identify (in brainwide fashion) the structurally- and molecularly-defined circuit elements at the intersection of reward and aversion, by which the vertebrate brain alters behavioral responses to aversive stimuli. In Aim 1, we develop next-gen CLARITY adapted to these paradigms to obtain brainwide wiring and molecular identification of all cells that are specifically recruited (active) in this key behavior (all registered to genetically-encoded Ca2+ sensor-derived activity data collected during the aversion- suppression behaviors). In Aim 2, using the tools from Aim 1 in combination with our latest optogenetic control methods, we will test specific circuit-activity hypotheses for causality in implementing cross-category modulation of aversion. In addition to the novel circuit targets that will emerge from the brainwide unbiased investigation of Aim 1, we already have specific circuit-level hypotheses to test based upon our existing preliminary data, ensuring that the later Aims of the proposal stand on an already-solid foundation. We hypothesize that this candidate circuit activity (in a tunable subset of projections from mPFC to specific subcortical structures) causes diminished behavioral impact of negative-valence stimuli via disrupted internal representation (and experience) of aversive stimuli. And in Aim 3, building on (and guided by) our identification of circuit elements that are naturally and causally involved in suppression of aversive responses, in this Aim we achieve single-cell real-time resolution during behavior. In the fiber-readout strategy of Aim 1 and 2; activity dynamics emerge as a single time-series from the fiber; as valuable as these data are, it is possible that signal increases could arise from altered synchrony or spread of activity in the region rather than from increased activity in a specific subset of target neurons. Single-cell resolution in causally implicated ensembles here will not only resolve this fundamental question, but also allow deep molecular profiling of the specific cells causally involved, with clear basic and translational implications. Identifying this circuitry will not only provide insight into the basic science of reward and aversion, but also will advance potentially revolutionary understanding and targeting of circuit elements that may be causal (or therapeutic) in human substance-use and neuropsychiatric disorders.