Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
Ann N Y Acad Sci. 2010 Feb;1187:140-7. doi: 10.1111/j.1749-6632.2009.05155.x.
The addictive consequences of abused substances depend upon activation of neurons in reward centers of the brain. Investigations aimed at determining the underlying basis for substance abuse have resulted in breakthroughs related to drug actions on normal neural processes; for example, the singular role of dopamine as the basis for drug addiction has been revised to include effects that, with other transmitter systems, produce changes in target neuronal firing that are different from those previously assumed, including "reward value" at the neuronal and systems levels and changes in the significance of pursued stimuli as a function of motivational state, context, effort, salience, and cognitive demand. Studies comparing these factors directly show differences between the actions of abused substances and less potent food-related rewards. Characterization of the change in reward-encoding processes for drug and natural rewards has provided insight into how abused substances gain control over behavior. This report explores how abused drugs alter neuron firing in reward-sensitive brain regions and how those alterations effect drug-seeking activity in animals and humans.
滥用物质的成瘾后果取决于大脑奖励中心神经元的激活。旨在确定物质滥用基础的研究已经取得了突破性进展，这些进展与药物对正常神经过程的作用有关；例如，多巴胺作为药物成瘾基础的单一作用已被修订为包括其他递质系统的作用，这些作用会导致靶神经元放电的变化，与以前假设的不同，包括神经元和系统水平的“奖励价值”以及作为动机状态、情境、努力、显著性和认知需求函数的被追求刺激的意义的变化。直接比较这些因素的研究表明，滥用物质和效力较低的与食物相关的奖励之间的作用存在差异。对药物和天然奖励的奖励编码过程变化的特征描述提供了对滥用物质如何控制行为的深入了解。本报告探讨了滥用药物如何改变奖励敏感脑区的神经元放电，以及这些改变如何影响动物和人类的觅药活动。
