Xu Jiansong, Mendrek Adrianna, Cohen Mark S, Monterosso John, Rodriguez Paul, Simon Sara L, Brody Arthur, Jarvik Murray, Domier Catherine P, Olmstead Richard, Ernst Monique, London Edythe D
Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA.
Biol Psychiatry. 2005 Jul 15;58(2):143-50. doi: 10.1016/j.biopsych.2005.03.028.
When nicotine-dependent human subjects abstain from cigarette smoking, they exhibit deficits in working memory. An understanding of the neural substrates of such impairments may help to understand how nicotine affects cognition. Our aim, therefore, was to identify abnormalities in the circuitry that mediates working memory in nicotine-dependent subjects after they initiate abstinence from smoking.
We used blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to study eight smokers while they performed a letter version of the N-Back working memory task under satiety (< or = 1.5 hours abstinence) and abstinence (> or = 14 hours abstinence) conditions.
Task-related activity in the left dorsal lateral prefrontal cortex (DLPFC) showed a significant interaction between test session (satiety, abstinence) and task load (1-back, 2-back, and 3-back). This interaction reflected the fact that task-related activity in the satiety condition was relatively low during performance of the 1-back task but greater at the more difficult task levels, whereas task-related activity in the abstinence condition was relatively high at the 1-back level and did not increase at the more difficult task levels.
We conclude that neural processing related to working memory in the left DLPFC is less efficient during acute abstinence from smoking than at smoking satiety.
当尼古丁依赖的人类受试者戒烟时，他们会出现工作记忆缺陷。了解此类损伤的神经基质可能有助于理解尼古丁如何影响认知。因此，我们的目的是确定尼古丁依赖受试者开始戒烟后介导工作记忆的神经回路中的异常情况。
我们使用血氧水平依赖（BOLD）功能磁共振成像（fMRI）来研究8名吸烟者，他们在饱腹（禁欲时间≤1.5小时）和禁欲（禁欲时间≥14小时）条件下执行字母版N-回溯工作记忆任务。
左背外侧前额叶皮层（DLPFC）中与任务相关的活动在测试阶段（饱腹、禁欲）和任务负荷（1-回溯、2-回溯和3-回溯）之间显示出显著的相互作用。这种相互作用反映了这样一个事实，即在饱腹状态下，与任务相关的活动在执行1-回溯任务时相对较低，但在更困难的任务水平时更高，而在禁欲状态下，与任务相关的活动在1-回溯水平时相对较高，在更困难的任务水平时并未增加。
我们得出结论，在急性戒烟期间，左DLPFC中与工作记忆相关的神经处理效率低于吸烟饱腹时。
