Scott David J, Stohler Christian S, Egnatuk Christine M, Wang Heng, Koeppe Robert A, Zubieta Jon-Kar
Department of Psychiatry and Molecular and Behavioral Neuroscience Institute, The University of Michigan, Ann Arbor, MI 48109-0720, USA.
Neuron. 2007 Jul 19;55(2):325-36. doi: 10.1016/j.neuron.2007.06.028.
Expectations, positive or negative, are modulating factors influencing behavior. They are also thought to underlie placebo effects, impacting perceptions and biological processes. Using healthy human subjects, we examined the role of the nucleus accumbens (NAC), a region centrally involved in the encoding of reward expectation, in the formation of placebo responses. Employing functional molecular imaging, activation of NAC dopamine (DA) release was observed during placebo administration and related to its anticipated effects, perception-anticipation mismatches, and placebo effect development. In additional functional MRI studies, the expectation of monetary gain increased NAC synaptic activity in a manner proportional to placebo-induced DA release, anticipated effects, perception-anticipation differentials, and actual placebo effects. Individual variations in NAC response to reward expectation accounted for 28% of the variance in the formation of placebo analgesia.
期望，无论积极还是消极，都是影响行为的调节因素。它们也被认为是安慰剂效应的基础，影响着感知和生物过程。我们使用健康人类受试者，研究了伏隔核（NAC）在安慰剂反应形成中的作用，伏隔核是一个在奖励期望编码中起核心作用的区域。采用功能分子成像技术，在给予安慰剂期间观察到伏隔核多巴胺（DA）释放的激活，且其与预期效果、感知 - 预期不匹配以及安慰剂效应的发展有关。在另外的功能磁共振成像研究中，对金钱收益的期望以与安慰剂诱导的DA释放、预期效果、感知 - 预期差异以及实际安慰剂效应成比例的方式增加了伏隔核的突触活动。伏隔核对奖励期望反应的个体差异占安慰剂镇痛形成中28%的方差。
