Jacobsen Leslie K, D'Souza D Cyril, Mencl W Einar, Pugh Kenneth R, Skudlarski Pawel, Krystal John H
Department of Psychiatry, Yale University School of Medicine, 100 York Street #28, West Haven, CT 06511, USA.
Biol Psychiatry. 2004 Apr 15;55(8):850-8. doi: 10.1016/j.biopsych.2003.12.023.
Nicotine in tobacco smoke can improve functioning in multiple cognitive domains. High rates of smoking among schizophrenic patients may reflect an effort to remediate cognitive dysfunction. Our primary aim was to determine whether nicotine improves cognitive function by facilitating activation of brain regions mediating task performance or by facilitating functional connectivity.
Thirteen smokers with schizophrenia and 13 smokers with no mental illness were withdrawn from tobacco and underwent functional magnetic resonance imaging (fMRI) scanning twice, once after placement of a placebo patch and once after placement of a nicotine patch. During scanning, subjects performed an n-back task with two levels of working memory load and of selective attention load.
During the most difficult (dichotic 2-back) task condition, nicotine improved performance of schizophrenic subjects and worsened performance of control subjects. Nicotine also enhanced activation of a network of regions, including anterior cingulate cortex and bilateral thalamus, and modulated thalamocortical functional connectivity to a greater degree in schizophrenic than in control subjects during dichotic 2-back task performance.
In tasks that tax working memory and selective attention, nicotine may improve performance in schizophrenia patients by enhancing activation of and functional connectivity between brain regions that mediate task performance.
烟草烟雾中的尼古丁可改善多个认知领域的功能。精神分裂症患者的高吸烟率可能反映了其改善认知功能障碍的努力。我们的主要目的是确定尼古丁是通过促进介导任务表现的脑区激活还是通过促进功能连接来改善认知功能。
13名患有精神分裂症的吸烟者和13名无精神疾病的吸烟者戒烟，并接受两次功能磁共振成像（fMRI）扫描，一次在佩戴安慰剂贴片后，一次在佩戴尼古丁贴片后。在扫描过程中，受试者执行具有两种工作记忆负荷和选择性注意负荷水平的n-back任务。
在最困难的（双耳分听2-back）任务条件下，尼古丁改善了精神分裂症患者的表现，却恶化了对照组受试者的表现。在双耳分听2-back任务表现期间，尼古丁还增强了包括前扣带回皮质和双侧丘脑在内的区域网络的激活，并在精神分裂症患者中比在对照组受试者中更大程度地调节了丘脑皮质功能连接。
在考验工作记忆和选择性注意的任务中，尼古丁可能通过增强介导任务表现的脑区之间的激活和功能连接来改善精神分裂症患者的表现。
