Department of Radiology, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD.
Nicotine Tob Res. 2018 Mar 6;20(4):440-447. doi: 10.1093/ntr/ntx168.
Nicotine dependence (ND) is a chronic, relapsing mental disorder characterized by compulsive cigarette seeking and smoking. Although the cerebellum plays an increasingly implicated role in ND, the exact cerebellar alterations in ND remain unclear. Identifying the localization of these cerebellar abnormalities in ND may help to further understand the role of the cerebellum in ND. Thus, we investigated the structural and functional alterations in the cerebellum in a large sample of smokers using the spatially unbiased infratentorial template (SUIT).
High-resolution structural magnetic resonance imaging (MRI) data were acquired from 85 smokers and 41 nonsmokers. We applied voxel-based morphometry (VBM) and the SUIT cerebellar atlas to compare the cerebellar gray matter (GM) volume between smokers and nonsmokers. Using resting-state functional MRI data, we also performed seed-based functional connectivity (FC) analysis to examine the functional correlates of the GM volume changes.
Both VBM and lobular analyses revealed smaller GM volume in the bilateral Crus I in smokers. The GM volume of the left Crus I was inversely correlated with the severity of nicotine dependence as assessed by Fagerström Test for Nicotine Dependence (r = -.268, p = .013). We also found reduced FC between the bilateral Crus I and brain regions involved in the default mode network and motor system, as well as the frontal and temporal cortex in smokers.
Our results indicate that decreased cerebellar GM volume and corticocerebellar FC are associated with ND, and these may underlie the core ND phenotypes, including automatized smoking behavior, cognitive, and emotional deficits.
As smoking remains a worldwide public health problem, identifying the related neural alterations may help to understand the pathophysiology of ND. Based on previous findings in the cerebellum, we investigated the localization of the GM differences and related FC changes in ND subjects. Our findings highlight altered corticocerebellar circuits in ND, suggesting an association between the cerebellum and the phenotypes of ND.
尼古丁依赖（ND）是一种慢性、复发性精神障碍，表现为强制性吸烟和吸烟。尽管小脑在 ND 中的作用越来越受到关注，但 ND 中小脑的确切改变仍不清楚。确定 ND 中这些小脑异常的定位可能有助于进一步了解小脑在 ND 中的作用。因此，我们使用空间无偏下脑模板（SUIT）研究了大量吸烟者小脑的结构和功能变化。
从 85 名吸烟者和 41 名非吸烟者中获取高分辨率结构磁共振成像（MRI）数据。我们应用基于体素的形态计量学（VBM）和 SUIT 小脑图谱比较吸烟者和非吸烟者之间小脑灰质（GM）体积。使用静息状态功能磁共振成像数据，我们还进行了种子功能连接（FC）分析，以检查 GM 体积变化的功能相关性。
VBM 和叶分析均显示吸烟者双侧 Crus I 的 GM 体积较小。左 Crus I 的 GM 体积与尼古丁依赖程度呈负相关，尼古丁依赖程度评估为 Fagerström 尼古丁依赖测试（r = -.268，p =.013）。我们还发现吸烟者双侧 Crus I 与默认模式网络和运动系统以及额叶和颞叶皮层之间的 FC 减少。
我们的研究结果表明，小脑 GM 体积减少和皮质小脑 FC 与 ND 相关，这些可能是 ND 的核心表型的基础，包括自动化吸烟行为、认知和情绪缺陷。
由于吸烟仍然是一个全球性的公共卫生问题，确定相关的神经改变可能有助于理解 ND 的病理生理学。基于小脑的先前研究结果，我们研究了 ND 患者 GM 差异和相关 FC 变化的定位。我们的研究结果强调了 ND 中皮质小脑回路的改变，提示小脑与 ND 表型之间存在关联。
