Kumari Veena, Gray Jeffrey A, ffytche Dominic H, Mitterschiffthaler Martina T, Das Mrigen, Zachariah Elizabeth, Vythelingum Goparlen N, Williams Steven C R, Simmons Andrew, Sharma Tonmoy
Department of Psychology, Institute of Psychiatry, King's College, London, UK.
Neuroimage. 2003 Jul;19(3):1002-13. doi: 10.1016/s1053-8119(03)00110-1.
To elucidate the neural correlates of cognitive effects of nicotine, we examined behavioral performance and blood oxygenation level-dependent regional brain activity, using functional magnetic resonance imaging, during a parametric "n-back" task in healthy nonsmoking males after the administration of nicotine (12 microg/kg body weight) or saline. Nicotine, compared to placebo, improved accuracy (P = 0.008) in all active conditions (2%-11%), and had a load-specific effect on latency (P = 0.004; 43.78% decrease at the highest memory load). Within a network of parietal and frontal areas activated by the task (P < 0.05, corrected at the voxel level), nicotine produced an increased response (P < 0.05; uncorrected within the regions of interest) in the anterior cingulate, superior frontal cortex, and superior parietal cortex. It also produced an increased response in the midbrain tectum in all active conditions and in the parahippocampal gyrus, cerebellum, and medial occipital lobe during rest (P = 0.05; uncorrected). The present observations point to altered neuronal activity in a distributed neural network associated with on-line task monitoring and attention and arousal systems as underlying nicotine-related enhancement of attention and working memory in human subjects.
为了阐明尼古丁认知效应的神经关联，我们在健康非吸烟男性接受尼古丁（12微克/千克体重）或生理盐水给药后，使用功能磁共振成像，在参数化“n-back”任务期间检查了行为表现和血氧水平依赖的局部脑活动。与安慰剂相比，尼古丁在所有活跃条件下提高了准确性（P = 0.008）（提高了2%-11%），并且对潜伏期有负荷特异性影响（P = 0.004；在最高记忆负荷下减少了43.78%）。在任务激活的顶叶和额叶区域网络内（P < 0.05，体素水平校正），尼古丁在前扣带回、额上回和顶上回产生了增强的反应（P < 0.05；在感兴趣区域内未校正）。在所有活跃条件下，尼古丁还在中脑顶盖产生了增强的反应，在休息时在海马旁回、小脑和枕叶内侧也产生了增强的反应（P = 0.05；未校正）。目前的观察结果表明，与在线任务监测以及注意力和唤醒系统相关的分布式神经网络中的神经元活动发生了改变，这是尼古丁相关的人类受试者注意力和工作记忆增强的基础。
