Department of Psychiatry, McGill University, Montréal, Québec, Canada.
PLoS One. 2012;7(1):e28370. doi: 10.1371/journal.pone.0028370. Epub 2012 Jan 4.
Dopamine neurotransmission influences approach toward rewards and reward-related cues. The best cited interpretation of this effect proposes that dopamine mediates the pleasure that commonly accompanies reward. This hypothesis has received support in some animal models and a few studies in humans. However, direct assessments of the effect of transiently increasing dopamine neurotransmission have been largely limited to the use of psychostimulant drugs, which elevate brain levels of multiple neurotransmitters in addition to dopamine. In the present study we tested the effect of more selectively elevating dopamine neurotransmission, as produced by administration of the immediate dopamine precursor, L-DOPA (0, 100/25, 200/50 mg, Sinemet), in healthy human volunteers. Neither dose altered positive mood. The results suggest that dopamine neurotransmission does not directly influence positive mood in humans.
多巴胺神经递质传递影响对奖励和与奖励相关的线索的接近程度。对这种影响的最佳解释是，多巴胺介导了通常伴随着奖励的愉悦感。这一假设在一些动物模型和少数人类研究中得到了支持。然而，对多巴胺神经递质传递的瞬时增加的影响的直接评估在很大程度上仅限于使用精神兴奋剂药物，这些药物除了多巴胺之外，还会提高大脑中多种神经递质的水平。在本研究中，我们测试了更选择性地提高多巴胺神经递质传递的效果，方法是给健康的人类志愿者服用直接的多巴胺前体 L-DOPA（0、100/25、200/50 毫克，Sinemet）。两种剂量都没有改变积极的情绪。结果表明，多巴胺神经递质传递不会直接影响人类的积极情绪。
