中文摘要：

目的研究母爱剥夺对大鼠脑伏隔核多巴胺受体2（DRD2）基因表达的影响，探索DNA甲基化是否参与调控DRD2基因的表达。方法20只新生大鼠被随机分为母爱剥夺组（8只）和对照组（12只），母爱剥夺组大鼠于哺乳期每天接受6h母爱剥夺；12周龄时，采用旷场试验评估大鼠的焦虑水平和探索能力，并采用逆转录聚合酶链反应检测伏隔核DRD2受体mRNA表达水平，用亚硫酸测序法检测DRD2基因启动子区DNA甲基化水平。结果（1）母爱剥夺组爬行总格数[（24±8）个]和直立次数[（10．1±2．0）次]少于对照组[分别为（44±8）个，（15．8±1．8）次；t=-5．12和-2．11，P〈0．01～0．05]。（2）母爱剥夺组大鼠脑内伏隔核DRD2mRNA表达（0．224±0．064）低于对照组（0．587±0．099；t=-7．50，P〈0．05）；两组DRD2基因启动子区的DNA甲基化水平差异无统计学意义（P〉0．05）。结论母爱剥夺大鼠成年以后在新奇环境中的焦虑水平增加，探索能力下降；母爱剥夺影响大鼠多巴胺系统DRD2基因表达，而DNA甲基化不参与调控基因表达。

英文摘要：

Objective To explore the effect of maternal deprivation on gene expression of dopamine receptor 2 （DRD2） in adult rats nucleus accumbens and whether DNA methylation was involved in its expression regulatory mechanism. Methods Twenty newborn rats were randomly divided into two groups, the maternal deprivation group （ n = 8） were deprived from their mother 6 hours per day during lactation, while the controls （n = 12） without any treatment. When they grew up to twelve weeks, their spontaneous anxiety levels and the exploratory ability in novel environments were assessed with open-field test. After behavior test, rats were sacrificed and nucleus accumbens were isolated. DRD2 mRNA expression level in nucleus accumens was detected by using reverse transcription-PCR, and its DNA methylation levels were detected with bisulfated DNA sequencing. Results （1） Open-field test revealed that the total number of grilles crossed and erection in maternal deprivation group [ grilles crossed of （24 ± 8 ） ; erection number of （10.1±2.0）] were less than that in the controls [（44±8）; （15.8±1.8）; P〈0.01-0.05]. （2） The expression level of DRD2 mRNA was significantly lower in maternal deprivation group （0. 224 ± 0. 064 ） than eontrol group （0. 586 ±0. 099） （P 〈 0. 05 ）. However, the DNA methylation levels in the promoter region of DRD2 were not signifieantly different between the two groups. Conclusions Maternal deprivation could influence the DRD2 genc expression, but DNA methylation may not be involved.