Division of Endocrinology, Metabolism, and Diabetes, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
Nat Neurosci. 2019 Nov;22(11):1820-1833. doi: 10.1038/s41593-019-0506-0. Epub 2019 Oct 14.
Basal amygdala (BA) neurons guide associative learning via acquisition of responses to stimuli that predict salient appetitive or aversive outcomes. We examined the learning- and state-dependent dynamics of BA neurons and ventral tegmental area (VTA) dopamine (DA) axons that innervate BA (VTA) using two-photon imaging and photometry in behaving mice. BA neurons did not respond to arbitrary visual stimuli, but acquired responses to stimuli that predicted either rewards or punishments. Most VTA axons were activated by both rewards and punishments, and they acquired responses to cues predicting these outcomes during learning. Responses to cues predicting food rewards in VTA axons and BA neurons in hungry mice were strongly attenuated following satiation, while responses to cues predicting unavoidable punishments persisted or increased. Therefore, VTA axons may provide a reinforcement signal of motivational salience that invigorates adaptive behaviors by promoting learned responses to appetitive or aversive cues in distinct, intermingled sets of BA excitatory neurons.
基底杏仁核 (BA) 神经元通过获取对预测显著奖赏或惩罚结果的刺激的反应来指导联想学习。我们使用双光子成像和行为小鼠中的光度测定法研究了基底杏仁核 (VTA) 神经元和支配基底杏仁核的腹侧被盖区 (VTA) 多巴胺 (DA) 轴突的学习和状态依赖性动力学。BA 神经元对任意视觉刺激没有反应，但对预测奖赏或惩罚的刺激会产生反应。大多数 VTA 轴突被奖赏和惩罚激活，并且在学习过程中对预测这些结果的线索产生反应。在饥饿的小鼠中，VTA 轴突和 BA 神经元对预测食物奖赏的线索的反应在饱食后被强烈减弱，而对预测不可避免惩罚的线索的反应则持续或增加。因此，VTA 轴突可能提供动机显着性的强化信号，通过促进对奖赏或惩罚线索的学习反应，从而激发适应性行为，在不同的、交织在一起的基底杏仁核兴奋性神经元集中。
