Contribution of dopamine to risk attitude across the lifespan

描述(由申请者提供)：我们社会中的个人需要通过整合大量可用信息来做出复杂的经济选择，这些选择往往具有不确定的结果。对人生所有阶段决策的这一日常要求，加上寿命的延长和社会最年轻和最年长成员获取信息的日益增多，使评估不同年龄段决策的潜在差异成为一个关键的研究领域。在具有确定和不确定结果的竞争选项中进行有利的选择是个人对奖励结果的主观评估和基于预测信息准确估计这些结果所需的强化学习过程的产物。因此，风险下决策的神经经济学框架结合了与年龄相关的主观评估差异和强化学习的贡献，为洞察整个生命周期中选择行为的潜在基础提供了强大的工具。这项拟议工作的主要目标是在整个生命周期内建立风险下决策的行为和神经生物学特征，并考察主观回报评估和强化学习在不同生命阶段对这些特征的贡献。我们假设，从青春期到成年期和衰老期间，多巴胺信号的发育/成熟变化是通过对决策机构的这些关键组成部分进行特定年龄的编码而对选择行为做出根本贡献的。我们提出了在青春期、成年期和老年大鼠的概率决策、强化学习和主观奖赏评估过程中检测腹侧纹状体中的多巴胺信号的三个特定目标。

DESCRIPTION (provided by applicant): Individuals in our society are required to make complex economic choices, often with uncertain outcomes, by integrating large amounts of information available to inform those choices. This daily requirement for decision making at all stages of life, together with increasing life spans and a growing accessibility to information among the youngest and eldest members of society, makes an evaluation of potential differences in decision making across age groups a critical area of research. Choosing advantageously among competing options with certain and uncertain outcomes is a product of individual subjective valuation of rewarding outcomes and the reinforcement learning processes required for accurately estimating those outcomes based on predictive information. Accordingly, a neuroeconomic framework of decision making under risk incorporating the contribution of age-related distinctions in subjective valuation and reinforcement learning provides a powerful tool for insight into the underlying substrates of choice behavior across the lifespan. The primary goal of the proposed work is to establish behavioral and neurobiological profiles of decision making under risk across the lifespan and examine the contribution of subjective reward valuation and reinforcement learning to these profiles at different life stages. We hypothesize that developmental/maturational changes in dopamine signaling from adolescence through adulthood and senescence is a fundamental contributor to choice behavior through the age-specific encoding of these essential components to the decision-making apparatus. We propose three specific aims examining dopamine signaling in the ventral striatum during probabilistic decision making, reinforcement learning, and subjective reward valuation in adolescent, adult, and aged rats.