Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, California.
Department of Pharmacology and Toxicology, and Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
Int J Neuropsychopharmacol. 2018 Sep 1;21(9):800-808. doi: 10.1093/ijnp/pyy054.
Although nicotine alters serotonergic neurochemistry, clinical trials of serotonergic medications for smoking cessation have provided mixed results. Understanding the role of serotonergic dysfunction in tobacco use disorder may advance development of novel pharmacotherapies.
Functional magnetic resonance imaging was used to measure resting-state functional connectivity of the raphe nuclei as an indicator of serotonergic function. Connectivity of the dorsal and median raphe nuclei was compared between 18 young smokers (briefly abstinent, ~40 minutes post-smoking) and 19 young nonsmokers (16-21 years old); connectivity was also examined in a separate sample of overnight-abstinent smokers (18-25 years old), before and after smoking the first cigarette of the day. Relationships between connectivity of the raphe nuclei with psychological withdrawal and craving were tested in smokers.
Connectivity of the median raphe nucleus with the right hippocampal complex was weaker in smokers than in nonsmokers and was negatively correlated with psychological withdrawal in smokers. In overnight-abstinent smokers, smoking increased connectivity of the median raphe nucleus with the right hippocampal complex, and the increase was positively correlated with the decrease in psychological withdrawal.
Relief of withdrawal due to smoking is potentially linked to the serotonergic pathway that includes the median raphe nucleus and hippocampal complex. These results suggest that serotonergic medications may be especially beneficial for smokers who endorse strong psychological withdrawal during abstinence from smoking.
尽管尼古丁会改变 5-羟色胺能神经化学，但 5-羟色胺能药物戒烟的临床试验结果喜忧参半。了解 5-羟色胺能功能障碍在烟草使用障碍中的作用，可能有助于开发新的药物疗法。
使用功能磁共振成像来测量中缝核的静息态功能连接，作为 5-羟色胺能功能的指标。将 18 名短暂戒烟（吸烟后约 40 分钟）的年轻吸烟者与 19 名年轻非吸烟者的中缝核背侧和中缝核中部的连接进行比较；还在另一个样本中观察了一夜戒烟的吸烟者（18-25 岁）在吸烟前和吸烟后的第一天的连接。在吸烟者中测试了中缝核与心理戒断和渴求的连接与心理渴求的关系。
与非吸烟者相比，吸烟者的中缝核中部与右侧海马复合体的连接较弱，与吸烟者的心理戒断呈负相关。在一夜戒烟的吸烟者中，吸烟增加了中缝核中部与右侧海马复合体的连接，而这种增加与心理戒断的减少呈正相关。
由于吸烟而导致的戒断缓解可能与包括中缝核和海马复合体在内的 5-羟色胺能通路有关。这些结果表明，5-羟色胺能药物可能对那些在戒烟期间有强烈心理戒断的吸烟者特别有益。
