Departments of Psychology and Neuroscience and Neurobiology, Duke University, Durham, North Carolina 27708.
Departments of Psychology and Neuroscience and Neurobiology, Duke University, Durham, North Carolina 27708
J Neurosci. 2021 Mar 3;41(9):1928-1940. doi: 10.1523/JNEUROSCI.1836-20.2020. Epub 2021 Jan 13.
Choice behavior is characterized by temporal discounting, i.e., preference for immediate rewards given a choice between immediate and delayed rewards. Agouti-related peptide (AgRP)-expressing neurons located in the arcuate nucleus of the hypothalamus (ARC) regulate food intake and energy homeostasis, yet whether AgRP neurons influence choice behavior and temporal discounting is unknown. Here, we demonstrate that motivational state potently modulates temporal discounting. Hungry mice (both male and female) strongly preferred immediate food rewards, yet sated mice were largely indifferent to reward delay. More importantly, selective optogenetic activation of AgRP-expressing neurons or their axon terminals within the posterior bed nucleus of stria terminalis (BNST) produced temporal discounting in sated mice. Furthermore, activation of neuropeptide Y (NPY) type 1 receptors (Y1Rs) within the BNST is sufficient to produce temporal discounting. These results demonstrate a profound influence of hypothalamic signaling on temporal discounting for food rewards and reveal a novel circuit that determine choice behavior. Temporal discounting is a universal phenomenon found in many species, yet the underlying neurocircuit mechanisms are still poorly understood. Our results revealed a novel neural pathway from agouti-related peptide (AgRP) neurons in the hypothalamus to the bed nucleus of stria terminalis (BNST) that regulates temporal discounting in decision-making.
选择行为的特征是时间折扣,即当在即时奖励和延迟奖励之间进行选择时,更倾向于即时奖励。位于下丘脑弓状核(ARC)中的 AgRP 表达神经元调节食物摄入和能量平衡,但 AgRP 神经元是否影响选择行为和时间折扣尚不清楚。在这里,我们证明了动机状态强烈调节时间折扣。饥饿的老鼠(雄性和雌性)强烈偏好即时食物奖励,但吃饱的老鼠对奖励延迟几乎漠不关心。更重要的是,选择性光遗传学激活 ARC 中的 AgRP 表达神经元或其轴突末梢在终纹床核(BNST)内产生了饱食老鼠的时间折扣。此外,BNST 内的神经肽 Y(NPY)1 型受体(Y1R)的激活足以产生时间折扣。这些结果表明,下丘脑信号对食物奖励的时间折扣有深远影响,并揭示了决定选择行为的新回路。时间折扣是在许多物种中发现的普遍现象,但潜在的神经回路机制仍知之甚少。我们的研究结果揭示了一条从下丘脑 AgRP 神经元到终纹床核(BNST)的新神经通路,该通路调节决策中的时间折扣。