尼古丁易感的脑结构特征的磁共振成像研究

本文旨在利用磁共振成像手段探究尼古丁易感个体的脑结构特征，即脑结构特性对尼古丁依赖程度的预测.选用成年雄性SD大鼠进行纵向研究，利用基于微型渗透压泵的间歇性给药方式对大鼠进行腹腔注射尼古丁14天，随后强制戒断14天.于第0、15、29天进行躯体戒断行为测试以量化其尼古丁依赖严重程度.对第1天的脑结构图像与戒断行为评分进行回归分析，结果发现尼古丁依赖严重程度与双侧前边缘皮层、左侧颗粒状岛叶皮层灰质体积和双侧丘脑白质体积呈负相关，与右侧海马CA1脑区和左侧丘脑灰质体积呈正相关.以上脑区的结构特征，能够作为尼古丁易感的生物标志物，在个体接触尼古丁之前预测其尼古丁依赖风险，对易感人群进行有针对性的早期干预.

Magnetic Resonance Imaging the Brain Structures Involved in Nicotine Susceptibility in Rats

The aim of this study is to identify brain structures involved in the individual difference of nicotine susceptibility in rats with longitudinal magnetic resonance imaging (MRI). Adult male Sprague-Dawley rats were subjected to intermittent intraperitoneal nicotine injection for 14 days using a mini-osmotic pump, followed by forced withdrawal for 14 days. Somatic withdrawal behavioral signs test was performed on day 0, 15, and 29 to quantify nicotine dependence. Correlation analyses between the withdrawal behavior score and structural MRI indices on day 1 (baseline scan) revealed that the severity of nicotine dependence was negatively correlated with the gray matter (GM) volumes in bilateral prelimbic cortex/left granular insular cortex and the white matter volume in bilateral thalamus, but positively correlated with the GM volumes in right hippocampal CA1/left thalamus. It is proposed that the aforementioned structural indices may be used as biomarkers for nicotine susceptibility, predicting the risk of nicotine dependence before individuals are exposed to nicotine.