Kimberg D Y, Aguirre G K, Lease J, D'Esposito M
Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Hum Brain Mapp. 2001 Apr;12(4):246-57. doi: 10.1002/1097-0193(200104)12:4<246::aid-hbm1019>3.0.co;2-9.
Studies of human subjects performing cognitive tasks on and off dopaminergic drugs have suggested a specific role of dopamine in cognitive processes, particularly in working memory and prefrontal "executive" functions. However, the cortical effects of these drugs have been poorly understood. We used functional magnetic resonance imaging (fMRI) to examine both task-specific and general changes in cortical activity associated with bromocriptine, a selective agonist for D-2 dopamine receptors. Bromocriptine resulted in task-specific modulations of task-related activity in three cognitive tasks. Across tasks, the overall effect of the drug was to reduce task-related activity. We also observed drug effects on behavior that correlated with individual differences in memory span. We argue that bromocriptine may show both task-specific modulation and task-general inhibition of neural activity due to dopaminergic neurotransmission.
对使用和停用多巴胺能药物的人类受试者执行认知任务的研究表明，多巴胺在认知过程中具有特定作用，尤其是在工作记忆和前额叶“执行”功能方面。然而，这些药物对皮层的影响一直未得到充分理解。我们使用功能磁共振成像（fMRI）来检查与D-2多巴胺受体的选择性激动剂溴隐亭相关的皮层活动的任务特异性和一般性变化。溴隐亭在三项认知任务中导致了与任务相关活动的任务特异性调节。在所有任务中，该药物的总体作用是减少与任务相关的活动。我们还观察到药物对行为的影响与记忆跨度的个体差异相关。我们认为，由于多巴胺能神经传递，溴隐亭可能对神经活动表现出任务特异性调节和任务一般性抑制。
