Gene expression in the human VTA of cases with alcohol abuse

Drugs of abuse including nicotine and alcohol elicit their effect by stimulating the mesocorticolimbic dopaminergic system. There is a high incidence of nicotine dependence in alcoholics. To date only limited data is available on the molecular mechanism underlying the action of alcohol and nicotine in the human brain. This study utilised gene expression screening to identify genes sensitive to chronic alcohol abuse within the ventral tegmental area of the human brain. Keywords: gene expression, brain, alcohol abuse, human, ventral tegmental area RNA was extracted individually from postmortem tissue samples of human ventral tegmental area (VTA) of 6 cases with and 6 cases without chronic alcohol abuse. RNA was also extracted from various other brain region (nucleus accumbens, prefronatl cortex). All samples were linearly amplified individually as described. Reference sample: Part of the aRNA from the VTA and those of the other brain regions was pooled. Cy3 dCTP labelling of each individual VTA aRNA sample. Cy5 dCTP labelling of reference pool. One labelled VTA aRNA sample was hybridised together with labelled reference aRNA. Samples of the same pathology (alcoholics or control cases) were treated as biological replicates. Student's t-test was used to reveal differentially expressed genes.

包括尼古丁与酒精在内的成瘾性药物，均通过激活中脑皮层边缘多巴胺能系统（mesocorticolimbic dopaminergic system）发挥药理效应。酒精成瘾人群中尼古丁依赖的发病率居高不下。迄今为止，关于酒精与尼古丁在人脑内发挥作用的分子机制，现有研究数据仍较为匮乏。本研究采用基因表达筛选技术，在人脑腹侧被盖区（ventral tegmental area, VTA）中筛选对慢性酒精滥用敏感的基因。
关键词：基因表达、大脑、酒精滥用、人类、腹侧被盖区
分别从12例人脑腹侧被盖区（VTA）的死后组织样本中提取RNA，其中6例为慢性酒精滥用者，另6例为非酒精滥用对照个体。同时从伏隔核、前额叶皮层等多个其他脑区中提取RNA。所有样本均按照既定方法进行独立线性扩增。
参照样本：将部分来自VTA的扩增RNA（amplified RNA, aRNA）与其他脑区的扩增RNA混合，制备参照样本。对每一份独立的VTA aRNA样本进行Cy3标记的脱氧胞苷三磷酸（dCTP）标记。对参照混合样本进行Cy5标记的脱氧胞苷三磷酸（dCTP）标记。将一份标记后的VTA aRNA样本与标记后的参照aRNA进行杂交。将病理状态一致的样本（酒精滥用者或对照个体）视为生物学重复样本。采用学生t检验（Student's t-test）筛选差异表达基因。