早年母爱剥夺对成年大鼠海马神经再生、BDNF和CREB表达的影响
|
摘要
目的
抑郁症是一种发病率较高的一种精神疾病,具有高致残性。在整个生命周期中,有15%以上的人群受到抑郁症的困扰,为家庭和社会带来了巨大的负担。目前有共识认为抑郁是基因与环境因素相互作用的结果,然而神经病理学机制仍不清楚。经典的单胺假说认为：5-HT、去甲肾上腺素、多巴胺等单胺神经递质的缺乏或不平衡是抑郁症发病的机制。虽然抗抑郁增强单胺系统效应的作用支持了这一假说,但是部分患者对抗抑郁药物反应不佳,而且一般在治疗几周或几个月后,药物临床疗效才出现。所以,单胺递质减少可能仅仅是导致抑郁症的起点机制。
临床流行病学研究发现,生命早期遭受创伤事件的人群,成年抑郁症易感性增加。基础研究也发现,早年遭受应激的啮齿类动物,成年后有抑郁样行为。同时研究也发现,抑郁症患者存在海马结构异常,如海马萎缩,神经元体积缩小、神经元和神经胶质细胞密度减低等。近年来,大量研究已经证实,哺乳动物海马存在新生的神经元,这些新生神经元不断填补到海马齿状回中,维持海马的正常生理功能。因此,多个易感基因与环境因素影响下的大脑特殊结构的神经可塑性紊乱可能是抑郁症发病的原因。
BDNF和CREB被认为对神经元的再生、存活、分化、生长发育起重要作用,有着防止神经元受损伤死亡、改善神经元病理状态、促进神经元再生及分化等生物效应,因此BDNF和CREB对维持中枢神经元的正常结构和生理功能具有重要的作用。BDNF和CREB的mRNA表达和蛋白水平降低将影响海马的神经再生等神经可塑性,影响海马的正常功能。
研究还显示,海马BDNF和CREB的mRNA表达和蛋白水平会影响海马的神经可塑性,而海马神经的可塑性又可能与抑郁症的发病有关。其他研究显示,生命早期应激可以增加成年抑郁易感性。因此,我们推测生命早期应激会改变海马神经再生、BDNF和CREB的mRNA表达和蛋白,导致抑郁易感性增加。在后期不良环境因素的影响下,可能导致抑郁症的发生。
为了论证我们的推测,本研究旨在探讨早年应激对成年大鼠海马神经再生、海马BDNFmRNA和蛋白、CREBmRNA和蛋白水平以及行为的影响；遭受早年应激的成年大鼠遭受慢性不可预见轻度应激时的行为和海马BDNFmRNA和蛋白CREBmRNA和蛋白水平的变化。
方法
1.分组
健康成年雌雄SD大鼠合笼,交配繁殖下一代。幼鼠出生后,移去雄性大鼠,留下母鼠与新生幼鼠在一起。挑出新生雄性幼鼠分为下列4组：
①正常对照组：出生后至第90天正常喂养;
②MD组：出生后第2天至第14天,每天与母鼠分离3h,第15天开始正常喂养至第90天；
③CUMS组：出生后至第90天正常喂养,而后给予21天的慢性轻度不可预见应激；
④双重应激组：出生后第2天至第14天,每天与母鼠分离3h,第15天开始正常喂养至第90天,而后给予21天的慢性轻度不可预见应激。
2.应激模型的建立
①MD模型：大鼠于出生后的第2天至第14天每天接受3h的母亲分离。每天9：30把幼鼠从母鼠巢中移出,单独放置于干净的盒子中,底部铺垫母巢中的木屑,温度与母巢一致,12：30再把幼鼠移回母巢中。
②CUMS模型：大鼠连续21天接受各种不同的不可预知的轻度应激：禁水(24h),禁食(48h),夹尾(1min),热刺激(45℃水浴,5min),明暗颠倒(24h),束缚(2h,2次),冰水游泳(4℃,5min)。每天采取的应激方式随意抽取。应激期间每只大鼠一个笼子孤养。
3.行为观察
①糖水偏好测验：试验前先禁水禁食24h,然后每只大鼠同时给予事先称重的2瓶水(一瓶为1%蔗糖水,另一瓶为自来水),60min后,取走2瓶进行定量,计算每只大鼠糖水偏爱百分比[糖水消耗量/(糖水消耗量+普通自来水消耗量)×100%]。糖水偏好降低反映快感缺乏,为抑郁症的核心症状之一。正常对照组、MD组在出生第90天进行糖水偏好测验,CUMS组和双重应激组在CUMS前后进行糖水偏好测验。
②旷场测验：实验在一个安静的房间内进行,时间均在9：00--12：00进行,2次测试房间温度、湿度相同。动物的活动情况采用动物运动轨迹记录分析系统(Ethovision系统,荷兰Noldus公司)采集和分析。旷场为120cmx90cmx35cm铁质敞箱,底部平分为25个方格,外围16个方格视为外围场地,中间9个方格视为内围场地。实验于早9：0012：00进行。实验时手提大鼠尾巴将大鼠轻轻放在箱底中心方格内,电脑开始记时,摄像头记录大鼠10min的行为,包括总行程、内围场地行程、直立次数。总行程直接反映动物的兴奋程度,内围场地行程反映大鼠的焦虑水平,直立次数反映大鼠的探索能力。正常对照组、MD组在出生第90天进行旷场测验,CUMS组和双重应激组在CUMS后进行旷场测验。
4. BrdU标记和免疫组化方法检测海马齿状回神经再生数量
糖水偏好测验和旷场测验结束后第2天,对正常对照组(n=12),MD组(n=12)用BrdU标记和免疫组化方法检测海马齿状回神经再生的数量。
①BrdU标记给大鼠腹腔注射BrdU (50mg/kg).每3h注射1次,共注射3次。24h后麻醉大鼠。经生理盐水和含4%多聚甲醛的磷酸盐缓冲液灌注固定。断头后,取出脑组织并进行再固定和脱水、包埋存于-70℃低温冰箱。
②免疫组化方法检测海马齿状回神经再生取出冰冻的大鼠脑组织,对其作连续冠状冰冻切片,每隔3张取1张切片组成1套；每套切片约5张,每片厚30μm,然后对上述切片,以BrdU小鼠单克隆抗体为一抗,生物素化小鼠抗体为二抗,进行免疫组化对海马齿状回BrdU标记细胞显色,并显微镜下计数。
5. RT-PCR方法检测海马BDNFmRNA、CREBmRNA的表达水平
正常对照组(n=12)、MD组(n=12)在糖水偏好测验和旷场测验结束后第2天以及CUMS组(n=12)和双重应激组(n=12)在CUMS后第2天断头,在冰冻铝盘上分离出海马,并储存在-70℃。样本化冻、粉碎,用逆转录聚合酶链反应技术(RT-PCR)方法检测海马BDNF和CREB的mRNA表达水平。采用GAPDH作为内参,以测得样品BDNF和CREB产物值除以GAPDH值,最终得到的比值为BDNFmRNA和CREB mRNA的相对含量。
6. Western blot方法检测海马BDNF和CREB的蛋白水平
取标本方法同RT-PCR方法。使用兔单克隆抗CREB抗体和兔单克隆抗BDNF抗体,用考马斯亮蓝染色法标记。以β-actin蛋白表达水平作为内参,以各样本与相应内参灰度值比值为蛋白相对含量。
结果
1.MD对成年雄性大鼠行为和海马齿状回神经再生的影响的结果：
(1)糖水偏好百分比,MD组明显少于正常对照组,差异具有统计学意义(P<0.01);
(2)大鼠在旷场内10分钟行为：旷场总行程、内围场地行程、直立次数,MD组均明显少于正常对照组(P<0.05)。
(3)MD组海马齿状回BrdU阳性细胞数明显少于正常对照组,差异有统计学意义(P<0.01)。
2.MD对成年雄性大鼠行为和海马BDNFmRNA和蛋白、CREBmRNA和蛋白的影响的结果：
(1)糖水偏好百分比,MD组明显少于正常对照组,差异具有统计学意义(P<0.01)：
(2)大鼠在旷场内10分钟行为：旷场总行程、内围场地行程、直立次数,MD组均明显少于正常对照组(P<0.05)；
(3) BDNF和CREB的mRNA表达及蛋白水平,MD组均明显低于正常对照组(P<0.05)。
3.CUMS和双重应激对成年大鼠行为和海马BDNFmRNA和蛋白、CREBmRNA和蛋白的影响的结果：
(1)糖水偏好百分比,母爱剥夺组、CUMS组、双重应激组明显低于正常对照组,差异具有统计学意义(P<0.05);CUMS组低于双重应激组,差异具有统计学意义(P<0.05)。
(2)大鼠在旷场内10分钟行为：旷场总行程、内围场地行程、直立次数,母爱剥夺组、CUMS组、双重应激组明显低于正常对照组,差异具有统计学意义(P<0.05)：CUMS组低于双重应激组,差异具有统计学意义(P<0.05)。
(3) BDNFmRNA和CREBmRNA表达水平,母爱剥夺组、CUMS组、双重应激组明显低于正常对照组,差异具有统计学意义(P<0.05);CUMS组低于双重应激组,差异具有统计学意义(P<0.05)。
(4) BDNF蛋白和CREB蛋白水平,母爱剥夺组、CUMS组、双重应激组明显低于正常对照组,差异具有统计学意义(P<0.05);CUMS组低于双重应激组,差异具有统计学意义(P<0.05)。
结论
(1)早年应激、成年慢性轻度应激和双重应激都可以影响行为和海马神经营养因子；
(2)早年应激改变成年大鼠海马齿状回神经再生以及海马神经营养因子水平,使大鼠产生抑郁样行为,可能增加抑郁易感性；
(3)早年应激改变成年后慢性轻度应激的行为反应和海马神经营养因子调节,导致对慢性轻度应激反应迟钝。
(4)早年应激对海马产生的长期影响可能增加抑郁症易感性,抑郁的发病还需要进一步的环境因素。
Objectives:
Depression is a prevalent, highly debilitating mental disorder affecting up to15%of the population at least once in their lifetime, with huge costs for society. Although there is consensus in depression about interplay between genetic and envirormiental factors, neurobiological mechanisms of depression are still not well known. The monoamine hypothesis of depression, based on a deficiency or imbalance of mono-amine neurotransmitters, such as serotonin, noradrenaline and dopamine, has been the leading explanation for the disorder for the last50years. The hypothesis is supported by the enhancing effect of all antidepressants on the monoaminergic systems. However, in clinical, part of patients are poor responders to antidepressant, even to more recently discovered medications. Furthermore, clinical response only occurs following weeks to months of treatment. These phenomena suggested that other than acute effects on mono-aminergic systemsare needed for antidepressant efficacy. The reduction of monoamines may be only the initiation of the mechanism of depression.
Clinical studies indicate that early adversity in the form of childhood lead to an increased vulnerability to develop depression later in life. Preclinical studies in rodents have shown that early stress results in depressive-like behaviour in adulthood. Mean-while, compared with controls, patients with depression are reported to present with abnormal structure of hippocampus (i.e.reduced hippocampal volume, reduced neurons volume, reduced density of neurons and glial cell). Recently, a number of researches prove that there are new neurons in hippocampus, added to the older cells in the dentate gyrus of hippocampus, maintaining the specific functions of this brain structure. The researchers gradually realized that an impairment of neural plasticity in specific areas of CNS may be part of a possible mechanism linking multiple susceptibility genes and environmental factors.
One thing to be noted is that BDNF and CREB are involved in cellular proliferation, migration, differentiation and maintenance in the developing brain, preventing neuron death, Improving the neuron pathological state and promoting the regeneration of neurons and differentiationo It is necessary to the survival and normal phy-siological function of mature central neurons. The reduction of BDNF mRNA and CREB mRNA expression and protein level has negative effctor in neural plasticity and normal function of hippocampus.
Given the relationship of early life stress, hippocampal neural plasticity and the mechanism of depression, we hypothesize that early life stress alter hippocampal neurogenesis, BDNF and CREB mRNA expression and protein level, leading to increased vulnerability to develop depression. The depression would occur when subject stress in adulthood.
The aim of the present study was therefore to investigate the effect of early MD and the double effects of MD and following CUMS on neurogenesis, BDNF and CREB mRNA expression and protein level of in hippocampus in adult rats.
Methods:
1. Groups
Male-female pairs were housed under normal conditions, to allow mating. Immediately after the rat pups were born, the adult males were removed, while the mothers remained with the pups. Newborn male rats were randomly divided into four groups. For these animals, birth was designated as postnatal day (PND)1:
①Control group:normal feeding form birth to the90th day;
②MD group:deprived from their mother3hours per day during PND2to PND4, normal feeding form PND15to PND90;
③CUMS group:normal feeding form birth to PND90, received21days CUMS after PND90;
④Double stress group:deprived from their mother3hours per day during PND2to PND4, normal feeding form PND15to PND90, received21days CUMS after PND90.
2. Stress models
①MD model:Maternal deprivation occurred from PND2until PND14for180mins between09:30-12:30h each day.The newborn male rats were removing the home cage to clean box with sawdust from home cage and the same temperature as home cage. After MD, the dam was placed back with the pups and returned to the colony housing room.
②CUMS model:Rats were subjected to various mild stressors for3weeks after PND90:water deprivation (24h), food deprivation (28h), tail clamping (1min), hot stress (45℃,5min), inversion of the light/dark cycle (24h), restraint (2hours,twice), ice water swimming (4℃,5min). Animals were exposed to stressors singly. Stressors were never presented simultaneously.
3. Behavior observation
①Sucrose preference tests:Sucrose preference tests consisted of first depriving the food and water from each rat's cage for a period of24h. Then, Water and1%sucrose were placed on the cages in standard drinking bottles with a5cm stainless-steel spout, and were presented for60min. The preference ratios were calculated as the amount of sucrose consumed divided by the total fluid intake. Anhedonia is defined as a reduction insucrose, which is a core symptom of depression. The sucrose preference tests were performed in control group and MD group at PND90, in CUMS group and double stress group after CUMS.
②Open field test:The tests were performed in a quiet room at9:00-12:00per day.Each experimental animal was placed in the center of a dimly illuminated rectangular cage (120cm×90cm×35cm).Behavioural responses were recorded using an automated video tracking system (Ethovision3.0, Noldus, the Netherlands) during a10min observational period in the open field. The bottom of field is divided into25same squares, outer16squares as outer zone and inner9squares as central zone. The frequencies of rearing (standing upright on the hind legs, while forepaws are free) was registered manually. Locomotor activity (the total and the central distance traveled) was quantified for10min using the video tracking system. Total travel, central distance traveled and the frequencies of rearing reflected the degree of excitement, the degree of anxiety and the exploration ability in rats, respectively. The Open field test were performed in control group and MD group at PND90,in CUMS group and double stress group after CUMS.
4. BrdU mark and immunohistochemical method analysis hippocampal neurogenesis
The hippocampal neurogenesis in Control group (n=12) and MD (n=12)group were analysed by marked and immunohistochemical method at the second day after the Sucrose preference tests and the open field test.
①BrdU mark were injected into rats abdominal (50mg/kg), Once every three hours, three times. Rats were anesthesia after24h, perfusion with physiological saline and4%Paraformaldehyde phosphate bufferand fixed. Then, the rats were beheaded, removed brain, fixed again, dehydrated and embed. The tissues were stored-70℃.
②Immunohistochemical method
Frozen rats tissue were taked out. The tissues were cut into coronal slices,
3interval pieces take1piece, each set of slice including5pieces,30μm per pieces. The first antibody is BrdU mice monoclonal antibody. The second antibody is biotin marked mice antibody., The number of BrdU marked cells in hippocampal dentate gyrus was counted using inmmunohistochemical method and microscope.
5.Real time PCR examination of the expression level of BDNFmRNA、CREBmRNA in hippocampus
Control group (n=12) and MD group (n=12) were beheaded at the second day after the Sucrose preference tests and the open field test. CUMS group (n=12) and double stress group (n=12) were beheaded at the second day after CUMS. Immediately after decapitation, the hippocampus were dissected from the brain on an ice-cold aluminium plate and stored-70℃. The samples were thawed and processed with RT-PCR measuring the mRNA expression levels of BDNF and CREB. GAPDH was used as internal standard for semiquantification. The values of BDNF and CREB product were normalized against the amount of PCR product for GAPDH obtained for the same RT sample.
6. Western blot examination of the protein level of BDNF and CREB
The method of making specimens was same as RT-PCR. Pulverized frozen hippo-campus samples were prepared and analyzed by quantitative immunoblotting. The rabbit monoclonal anti-CREB antibody (sc-186, Santa Cruz Biotechnology) and rabbit monoclonal anti-BDNF antibody (sc-20981, Santa Cruz Biotechnology) were used. β-Actin was used as internal standard. The expression of BDNF protein, CREB protein was normalized to β-Actin expression.
Results
1. Effects of early maternal deprivation on behavior and hippocampal neurogenesis in adult male rats
(1) The percentage of sucrose preference in MD group were significant less than that in the control group (P<0.01);
(2) Behaviors in open field for10minutes:The total distance traveled, the central distance traveled, the frequencies of rearing in MD group were all significant less than that in the control group (P<0.05);
(3)BrdU-labeled cells in the dentate gyrus in maternal deprivation group were significant less than that in contral group (P<0.01).
2. MD on behavior and BDNFmRNA/protein, CREBmRNA/protein level of hippocampus in adult male rats
(1) The percentage of sucrose preference in MD group were significant less than that in the control group (P<0.01);
(2) Behaviors in open field for10minutes:The total distance traveled, the central distance traveled, the frequencies of rearing in MD group were all significant less than that in the control group (P<0.05);
(3) MD group showed significant decrease in expression of BDNF/CREB mRNA and level of BDNF/CREB protein in hippocampus compared to control group in their adulthood (P<0.05).
3. CUMS and double stress on on behavior and BDNFmRNA/protein and CREB mRNA/protein level of hippocampus in adult male rats
(1) The percentage of sucrose preference in MD group, CUMS group and double stress group were significant less than that in control group (P<0.05); CUMS group were less than that double stress group (P<0.05);
(2) Behaviors in open field for10minutes:The total distance traveled, the central distance traveled, the frequencies of rearing in MD group, CUMS group and double stress group were significant less than that in control group (P<0.05); CUMS group were less than that double stress group (P<0.05);
(3) The expression of BDNF/CREB mRNA of hippocampus in MD group, CUMS group and double stress group were significant less than that in control group (P<0.05); CUMS group were less than that double stress group (P<0.05);
(4) The level of BDNF/CREB protein of hippocampus in MD group, CUMS group and double stress group were significant less than that in control group (P <0.05); CUMS group were less than that double stress group (P<0.05)。
Conclusions:
(1) Early life stress, chronic mild stress in adulthood and double stress all could alter behavior and the level of hippocampal neurotrophic factor in adult rat;
(2) Early life stress could alter hippocampal neurogenesis and the level of hippocampal neurotrophins in adult rat. It may have influence in susceptibility to depression disorders.
(3) Early stress could alter the response to chronic mild stress in adulthood, including behavior and the regulation of hippocampal neurotrophic factor:resulting a slow response to chronic mild stress in adulthood.
(4)Long-term effects of early stress on the hippocampus increased the susceptibility to depression. The incidence of depression also need further environmental factors.
抑郁症是一种发病率较高的一种精神疾病,具有高致残性。在整个生命周期中,有15%以上的人群受到抑郁症的困扰,为家庭和社会带来了巨大的负担。目前有共识认为抑郁是基因与环境因素相互作用的结果,然而神经病理学机制仍不清楚。经典的单胺假说认为：5-HT、去甲肾上腺素、多巴胺等单胺神经递质的缺乏或不平衡是抑郁症发病的机制。虽然抗抑郁增强单胺系统效应的作用支持了这一假说,但是部分患者对抗抑郁药物反应不佳,而且一般在治疗几周或几个月后,药物临床疗效才出现。所以,单胺递质减少可能仅仅是导致抑郁症的起点机制。
临床流行病学研究发现,生命早期遭受创伤事件的人群,成年抑郁症易感性增加。基础研究也发现,早年遭受应激的啮齿类动物,成年后有抑郁样行为。同时研究也发现,抑郁症患者存在海马结构异常,如海马萎缩,神经元体积缩小、神经元和神经胶质细胞密度减低等。近年来,大量研究已经证实,哺乳动物海马存在新生的神经元,这些新生神经元不断填补到海马齿状回中,维持海马的正常生理功能。因此,多个易感基因与环境因素影响下的大脑特殊结构的神经可塑性紊乱可能是抑郁症发病的原因。
BDNF和CREB被认为对神经元的再生、存活、分化、生长发育起重要作用,有着防止神经元受损伤死亡、改善神经元病理状态、促进神经元再生及分化等生物效应,因此BDNF和CREB对维持中枢神经元的正常结构和生理功能具有重要的作用。BDNF和CREB的mRNA表达和蛋白水平降低将影响海马的神经再生等神经可塑性,影响海马的正常功能。
研究还显示,海马BDNF和CREB的mRNA表达和蛋白水平会影响海马的神经可塑性,而海马神经的可塑性又可能与抑郁症的发病有关。其他研究显示,生命早期应激可以增加成年抑郁易感性。因此,我们推测生命早期应激会改变海马神经再生、BDNF和CREB的mRNA表达和蛋白,导致抑郁易感性增加。在后期不良环境因素的影响下,可能导致抑郁症的发生。
为了论证我们的推测,本研究旨在探讨早年应激对成年大鼠海马神经再生、海马BDNFmRNA和蛋白、CREBmRNA和蛋白水平以及行为的影响；遭受早年应激的成年大鼠遭受慢性不可预见轻度应激时的行为和海马BDNFmRNA和蛋白CREBmRNA和蛋白水平的变化。
方法
1.分组
健康成年雌雄SD大鼠合笼,交配繁殖下一代。幼鼠出生后,移去雄性大鼠,留下母鼠与新生幼鼠在一起。挑出新生雄性幼鼠分为下列4组：
①正常对照组：出生后至第90天正常喂养;
②MD组：出生后第2天至第14天,每天与母鼠分离3h,第15天开始正常喂养至第90天；
③CUMS组：出生后至第90天正常喂养,而后给予21天的慢性轻度不可预见应激；
④双重应激组：出生后第2天至第14天,每天与母鼠分离3h,第15天开始正常喂养至第90天,而后给予21天的慢性轻度不可预见应激。
2.应激模型的建立
①MD模型：大鼠于出生后的第2天至第14天每天接受3h的母亲分离。每天9：30把幼鼠从母鼠巢中移出,单独放置于干净的盒子中,底部铺垫母巢中的木屑,温度与母巢一致,12：30再把幼鼠移回母巢中。
②CUMS模型：大鼠连续21天接受各种不同的不可预知的轻度应激：禁水(24h),禁食(48h),夹尾(1min),热刺激(45℃水浴,5min),明暗颠倒(24h),束缚(2h,2次),冰水游泳(4℃,5min)。每天采取的应激方式随意抽取。应激期间每只大鼠一个笼子孤养。
3.行为观察
①糖水偏好测验：试验前先禁水禁食24h,然后每只大鼠同时给予事先称重的2瓶水(一瓶为1%蔗糖水,另一瓶为自来水),60min后,取走2瓶进行定量,计算每只大鼠糖水偏爱百分比[糖水消耗量/(糖水消耗量+普通自来水消耗量)×100%]。糖水偏好降低反映快感缺乏,为抑郁症的核心症状之一。正常对照组、MD组在出生第90天进行糖水偏好测验,CUMS组和双重应激组在CUMS前后进行糖水偏好测验。
②旷场测验：实验在一个安静的房间内进行,时间均在9：00--12：00进行,2次测试房间温度、湿度相同。动物的活动情况采用动物运动轨迹记录分析系统(Ethovision系统,荷兰Noldus公司)采集和分析。旷场为120cmx90cmx35cm铁质敞箱,底部平分为25个方格,外围16个方格视为外围场地,中间9个方格视为内围场地。实验于早9：0012：00进行。实验时手提大鼠尾巴将大鼠轻轻放在箱底中心方格内,电脑开始记时,摄像头记录大鼠10min的行为,包括总行程、内围场地行程、直立次数。总行程直接反映动物的兴奋程度,内围场地行程反映大鼠的焦虑水平,直立次数反映大鼠的探索能力。正常对照组、MD组在出生第90天进行旷场测验,CUMS组和双重应激组在CUMS后进行旷场测验。
4. BrdU标记和免疫组化方法检测海马齿状回神经再生数量
糖水偏好测验和旷场测验结束后第2天,对正常对照组(n=12),MD组(n=12)用BrdU标记和免疫组化方法检测海马齿状回神经再生的数量。
①BrdU标记给大鼠腹腔注射BrdU (50mg/kg).每3h注射1次,共注射3次。24h后麻醉大鼠。经生理盐水和含4%多聚甲醛的磷酸盐缓冲液灌注固定。断头后,取出脑组织并进行再固定和脱水、包埋存于-70℃低温冰箱。
②免疫组化方法检测海马齿状回神经再生取出冰冻的大鼠脑组织,对其作连续冠状冰冻切片,每隔3张取1张切片组成1套；每套切片约5张,每片厚30μm,然后对上述切片,以BrdU小鼠单克隆抗体为一抗,生物素化小鼠抗体为二抗,进行免疫组化对海马齿状回BrdU标记细胞显色,并显微镜下计数。
5. RT-PCR方法检测海马BDNFmRNA、CREBmRNA的表达水平
正常对照组(n=12)、MD组(n=12)在糖水偏好测验和旷场测验结束后第2天以及CUMS组(n=12)和双重应激组(n=12)在CUMS后第2天断头,在冰冻铝盘上分离出海马,并储存在-70℃。样本化冻、粉碎,用逆转录聚合酶链反应技术(RT-PCR)方法检测海马BDNF和CREB的mRNA表达水平。采用GAPDH作为内参,以测得样品BDNF和CREB产物值除以GAPDH值,最终得到的比值为BDNFmRNA和CREB mRNA的相对含量。
6. Western blot方法检测海马BDNF和CREB的蛋白水平
取标本方法同RT-PCR方法。使用兔单克隆抗CREB抗体和兔单克隆抗BDNF抗体,用考马斯亮蓝染色法标记。以β-actin蛋白表达水平作为内参,以各样本与相应内参灰度值比值为蛋白相对含量。
结果
1.MD对成年雄性大鼠行为和海马齿状回神经再生的影响的结果：
(1)糖水偏好百分比,MD组明显少于正常对照组,差异具有统计学意义(P<0.01);
(2)大鼠在旷场内10分钟行为：旷场总行程、内围场地行程、直立次数,MD组均明显少于正常对照组(P<0.05)。
(3)MD组海马齿状回BrdU阳性细胞数明显少于正常对照组,差异有统计学意义(P<0.01)。
2.MD对成年雄性大鼠行为和海马BDNFmRNA和蛋白、CREBmRNA和蛋白的影响的结果：
(1)糖水偏好百分比,MD组明显少于正常对照组,差异具有统计学意义(P<0.01)：
(2)大鼠在旷场内10分钟行为：旷场总行程、内围场地行程、直立次数,MD组均明显少于正常对照组(P<0.05)；
(3) BDNF和CREB的mRNA表达及蛋白水平,MD组均明显低于正常对照组(P<0.05)。
3.CUMS和双重应激对成年大鼠行为和海马BDNFmRNA和蛋白、CREBmRNA和蛋白的影响的结果：
(1)糖水偏好百分比,母爱剥夺组、CUMS组、双重应激组明显低于正常对照组,差异具有统计学意义(P<0.05);CUMS组低于双重应激组,差异具有统计学意义(P<0.05)。
(2)大鼠在旷场内10分钟行为：旷场总行程、内围场地行程、直立次数,母爱剥夺组、CUMS组、双重应激组明显低于正常对照组,差异具有统计学意义(P<0.05)：CUMS组低于双重应激组,差异具有统计学意义(P<0.05)。
(3) BDNFmRNA和CREBmRNA表达水平,母爱剥夺组、CUMS组、双重应激组明显低于正常对照组,差异具有统计学意义(P<0.05);CUMS组低于双重应激组,差异具有统计学意义(P<0.05)。
(4) BDNF蛋白和CREB蛋白水平,母爱剥夺组、CUMS组、双重应激组明显低于正常对照组,差异具有统计学意义(P<0.05);CUMS组低于双重应激组,差异具有统计学意义(P<0.05)。
结论
(1)早年应激、成年慢性轻度应激和双重应激都可以影响行为和海马神经营养因子；
(2)早年应激改变成年大鼠海马齿状回神经再生以及海马神经营养因子水平,使大鼠产生抑郁样行为,可能增加抑郁易感性；
(3)早年应激改变成年后慢性轻度应激的行为反应和海马神经营养因子调节,导致对慢性轻度应激反应迟钝。
(4)早年应激对海马产生的长期影响可能增加抑郁症易感性,抑郁的发病还需要进一步的环境因素。
Objectives:
Depression is a prevalent, highly debilitating mental disorder affecting up to15%of the population at least once in their lifetime, with huge costs for society. Although there is consensus in depression about interplay between genetic and envirormiental factors, neurobiological mechanisms of depression are still not well known. The monoamine hypothesis of depression, based on a deficiency or imbalance of mono-amine neurotransmitters, such as serotonin, noradrenaline and dopamine, has been the leading explanation for the disorder for the last50years. The hypothesis is supported by the enhancing effect of all antidepressants on the monoaminergic systems. However, in clinical, part of patients are poor responders to antidepressant, even to more recently discovered medications. Furthermore, clinical response only occurs following weeks to months of treatment. These phenomena suggested that other than acute effects on mono-aminergic systemsare needed for antidepressant efficacy. The reduction of monoamines may be only the initiation of the mechanism of depression.
Clinical studies indicate that early adversity in the form of childhood lead to an increased vulnerability to develop depression later in life. Preclinical studies in rodents have shown that early stress results in depressive-like behaviour in adulthood. Mean-while, compared with controls, patients with depression are reported to present with abnormal structure of hippocampus (i.e.reduced hippocampal volume, reduced neurons volume, reduced density of neurons and glial cell). Recently, a number of researches prove that there are new neurons in hippocampus, added to the older cells in the dentate gyrus of hippocampus, maintaining the specific functions of this brain structure. The researchers gradually realized that an impairment of neural plasticity in specific areas of CNS may be part of a possible mechanism linking multiple susceptibility genes and environmental factors.
One thing to be noted is that BDNF and CREB are involved in cellular proliferation, migration, differentiation and maintenance in the developing brain, preventing neuron death, Improving the neuron pathological state and promoting the regeneration of neurons and differentiationo It is necessary to the survival and normal phy-siological function of mature central neurons. The reduction of BDNF mRNA and CREB mRNA expression and protein level has negative effctor in neural plasticity and normal function of hippocampus.
Given the relationship of early life stress, hippocampal neural plasticity and the mechanism of depression, we hypothesize that early life stress alter hippocampal neurogenesis, BDNF and CREB mRNA expression and protein level, leading to increased vulnerability to develop depression. The depression would occur when subject stress in adulthood.
The aim of the present study was therefore to investigate the effect of early MD and the double effects of MD and following CUMS on neurogenesis, BDNF and CREB mRNA expression and protein level of in hippocampus in adult rats.
Methods:
1. Groups
Male-female pairs were housed under normal conditions, to allow mating. Immediately after the rat pups were born, the adult males were removed, while the mothers remained with the pups. Newborn male rats were randomly divided into four groups. For these animals, birth was designated as postnatal day (PND)1:
①Control group:normal feeding form birth to the90th day;
②MD group:deprived from their mother3hours per day during PND2to PND4, normal feeding form PND15to PND90;
③CUMS group:normal feeding form birth to PND90, received21days CUMS after PND90;
④Double stress group:deprived from their mother3hours per day during PND2to PND4, normal feeding form PND15to PND90, received21days CUMS after PND90.
2. Stress models
①MD model:Maternal deprivation occurred from PND2until PND14for180mins between09:30-12:30h each day.The newborn male rats were removing the home cage to clean box with sawdust from home cage and the same temperature as home cage. After MD, the dam was placed back with the pups and returned to the colony housing room.
②CUMS model:Rats were subjected to various mild stressors for3weeks after PND90:water deprivation (24h), food deprivation (28h), tail clamping (1min), hot stress (45℃,5min), inversion of the light/dark cycle (24h), restraint (2hours,twice), ice water swimming (4℃,5min). Animals were exposed to stressors singly. Stressors were never presented simultaneously.
3. Behavior observation
①Sucrose preference tests:Sucrose preference tests consisted of first depriving the food and water from each rat's cage for a period of24h. Then, Water and1%sucrose were placed on the cages in standard drinking bottles with a5cm stainless-steel spout, and were presented for60min. The preference ratios were calculated as the amount of sucrose consumed divided by the total fluid intake. Anhedonia is defined as a reduction insucrose, which is a core symptom of depression. The sucrose preference tests were performed in control group and MD group at PND90, in CUMS group and double stress group after CUMS.
②Open field test:The tests were performed in a quiet room at9:00-12:00per day.Each experimental animal was placed in the center of a dimly illuminated rectangular cage (120cm×90cm×35cm).Behavioural responses were recorded using an automated video tracking system (Ethovision3.0, Noldus, the Netherlands) during a10min observational period in the open field. The bottom of field is divided into25same squares, outer16squares as outer zone and inner9squares as central zone. The frequencies of rearing (standing upright on the hind legs, while forepaws are free) was registered manually. Locomotor activity (the total and the central distance traveled) was quantified for10min using the video tracking system. Total travel, central distance traveled and the frequencies of rearing reflected the degree of excitement, the degree of anxiety and the exploration ability in rats, respectively. The Open field test were performed in control group and MD group at PND90,in CUMS group and double stress group after CUMS.
4. BrdU mark and immunohistochemical method analysis hippocampal neurogenesis
The hippocampal neurogenesis in Control group (n=12) and MD (n=12)group were analysed by marked and immunohistochemical method at the second day after the Sucrose preference tests and the open field test.
①BrdU mark were injected into rats abdominal (50mg/kg), Once every three hours, three times. Rats were anesthesia after24h, perfusion with physiological saline and4%Paraformaldehyde phosphate bufferand fixed. Then, the rats were beheaded, removed brain, fixed again, dehydrated and embed. The tissues were stored-70℃.
②Immunohistochemical method
Frozen rats tissue were taked out. The tissues were cut into coronal slices,
3interval pieces take1piece, each set of slice including5pieces,30μm per pieces. The first antibody is BrdU mice monoclonal antibody. The second antibody is biotin marked mice antibody., The number of BrdU marked cells in hippocampal dentate gyrus was counted using inmmunohistochemical method and microscope.
5.Real time PCR examination of the expression level of BDNFmRNA、CREBmRNA in hippocampus
Control group (n=12) and MD group (n=12) were beheaded at the second day after the Sucrose preference tests and the open field test. CUMS group (n=12) and double stress group (n=12) were beheaded at the second day after CUMS. Immediately after decapitation, the hippocampus were dissected from the brain on an ice-cold aluminium plate and stored-70℃. The samples were thawed and processed with RT-PCR measuring the mRNA expression levels of BDNF and CREB. GAPDH was used as internal standard for semiquantification. The values of BDNF and CREB product were normalized against the amount of PCR product for GAPDH obtained for the same RT sample.
6. Western blot examination of the protein level of BDNF and CREB
The method of making specimens was same as RT-PCR. Pulverized frozen hippo-campus samples were prepared and analyzed by quantitative immunoblotting. The rabbit monoclonal anti-CREB antibody (sc-186, Santa Cruz Biotechnology) and rabbit monoclonal anti-BDNF antibody (sc-20981, Santa Cruz Biotechnology) were used. β-Actin was used as internal standard. The expression of BDNF protein, CREB protein was normalized to β-Actin expression.
Results
1. Effects of early maternal deprivation on behavior and hippocampal neurogenesis in adult male rats
(1) The percentage of sucrose preference in MD group were significant less than that in the control group (P<0.01);
(2) Behaviors in open field for10minutes:The total distance traveled, the central distance traveled, the frequencies of rearing in MD group were all significant less than that in the control group (P<0.05);
(3)BrdU-labeled cells in the dentate gyrus in maternal deprivation group were significant less than that in contral group (P<0.01).
2. MD on behavior and BDNFmRNA/protein, CREBmRNA/protein level of hippocampus in adult male rats
(1) The percentage of sucrose preference in MD group were significant less than that in the control group (P<0.01);
(2) Behaviors in open field for10minutes:The total distance traveled, the central distance traveled, the frequencies of rearing in MD group were all significant less than that in the control group (P<0.05);
(3) MD group showed significant decrease in expression of BDNF/CREB mRNA and level of BDNF/CREB protein in hippocampus compared to control group in their adulthood (P<0.05).
3. CUMS and double stress on on behavior and BDNFmRNA/protein and CREB mRNA/protein level of hippocampus in adult male rats
(1) The percentage of sucrose preference in MD group, CUMS group and double stress group were significant less than that in control group (P<0.05); CUMS group were less than that double stress group (P<0.05);
(2) Behaviors in open field for10minutes:The total distance traveled, the central distance traveled, the frequencies of rearing in MD group, CUMS group and double stress group were significant less than that in control group (P<0.05); CUMS group were less than that double stress group (P<0.05);
(3) The expression of BDNF/CREB mRNA of hippocampus in MD group, CUMS group and double stress group were significant less than that in control group (P<0.05); CUMS group were less than that double stress group (P<0.05);
(4) The level of BDNF/CREB protein of hippocampus in MD group, CUMS group and double stress group were significant less than that in control group (P <0.05); CUMS group were less than that double stress group (P<0.05)。
Conclusions:
(1) Early life stress, chronic mild stress in adulthood and double stress all could alter behavior and the level of hippocampal neurotrophic factor in adult rat;
(2) Early life stress could alter hippocampal neurogenesis and the level of hippocampal neurotrophins in adult rat. It may have influence in susceptibility to depression disorders.
(3) Early stress could alter the response to chronic mild stress in adulthood, including behavior and the regulation of hippocampal neurotrophic factor:resulting a slow response to chronic mild stress in adulthood.
(4)Long-term effects of early stress on the hippocampus increased the susceptibility to depression. The incidence of depression also need further environmental factors.
引文
[1]Heim C, Plotsky PM, Nemerof f CB. Importance of studying the contributions of early adverse experience to neurobiological findings in depression [J]. Neuro-psychopharmacology,2004,29(4):641-648.
[2]Gilmer WS, McKinney WT.Early experience and depressive disorders:human and non-human primate studies[J]. Journal of affective disorders,2003,75(2): 97-113.
[3]McCauley J, Kern DE Kolodner K, Dill L, Schroeder AF, DeChant HK, Ryden J, Derogatis LR, Bass EB. Clinical characteristics of women with a history of childhood abuse: unhealed wounds[J]. JAMA:the journal of the American Medical Association,1997,277(17):1362-1368.
[4]Tenant C. Parental loss in childhood relationship to adult psychiatric impairment and contact with psychiatric services[J]. Arch Gen Psychiat,1981, 38(2):309-315.
[5]Shamseddeen W, Asarnow JR,Clarke G,Vitiello B,Wagner KD, Birmaher B,Keller MB, Emslie G, Iyengar S, Ryan ND, McCracken JT, Porta G, Mayes T, Brent DA. Impact of physical and sexual abuse on treatment response in the treatment of resistant depression in adolescent study (TORDIA)[J]. Journal of the American Academy of Child and Adolescent Psychiatry,2011,50(3):293-301.
[6]Thakker-Varia S, Alder J. Neuropeptides in depression:Role of VGF[J]. Behavioural brain research,2009,197(2):262-278.
[7]Small SA,Schobel SA, Buxton RB,Witter MP, Barnes CA. A pathophysiological framework of hippocampal dysfunction in ageing and disease [J]. Nature reviews. Neuroscience,2011,12(10):585-601.
[8]Savitz J, DrevetsWC. Bipolar and major depressive disorder:neuroimaging the evelopmental-degenerative divide. Neuroscience and biobehavioral reviews[J].2009,33(5):699-771.
[9]Duman RS, Malberg J, Thome J. Neural plasticity to stress and antidepressant treatment [J]. Biological psychiatry,1999,46(9):1181-1191.
[10]Duman RS, Nakagawa S, Malberg J. Regulation of adult neurogenesis by anti-depressant treatment[J]. Neuropsychopharmacology:official publication of the American College of Neuropsychopharmacology,2001,25(6):836-844.
[11]Perera TD, Dwork AJ, Keegan KA, Thirumangalakudi L, Lipira CM, Joyce N, Lange C, Higley JD,Rosoklija G, Hen R, Sackeim HA, Coplan JD. Necessity of hippocampal neurogenesis for the therapeutic action of antidepressants in adult nonhuman primates [J]. PloS one,2011,6(4):e17600.
[12]Santarelli L, Saxe M, Cross C, Surget A, Battaglia F, Dulawa S, Weisstaub N, Lee J,Duman R, Arancio 0, Belzung C, Hen R. Requirement of hippocampal neurogenesis for the behavioral effects of antidepressants [J]. Science,2003,301 (5634):805-809.
[13]Aydemir C, Yalcin ES, Aksaray S, et al. Brain-derived neurotrophic factor (BDNF) changes in the serum of depressed women[J]. Prog Neuropsychopharmacol Biol Psychiatry,2006,30(7):1256.
[14]Shinizu E, Hashinoto K,Okamura N, et a.l Alterations of serum levels ofbrain-derived neurotrophic factor (BDNF) in depressed patients with or without antidepressants[J]. Biol Psychiatry,2003,54(1):70.
[15]Blendy JA. The role of CREB in depression and antidepressant treatment [J]. Biol Psychiatry,2006,59:1144-1150.
[16]Ru " edi-Bettschen D, Feldon J, Pryce C R. The impaired coping induced by early deprivation is reversed by chronic fluoxetine treatment in adult Fischer rats[J]. BehaviouralPharmacology,2004,15:413-421.
[17]MacQueen GM, Ramakrishnan K, Ratnasingan R, Chen B,Young LT. Desipramine treatment reduces the long-term behavioural and neurochemical sequelae of early-life maternal separation[J]. Int. J. Neuropsychopharmacol.2003b,6: 391-396.
[18]Macri S, Laviola G. Single episode of maternal deprivation and adult depressive profile in mice:interaction with cannabinoid exposure during adolescence [J]. Behav Brain Res,2004,154:231-238.
[19]Lippmann M, Bress A, Nemeroff CB, Plotsky PM, Monteggia LM. Long-term behavioural and molecular alterations associated with maternal separation in rats[J]. European Journal of Neuroscience,2007,25:3091-3098.
[20]朱熊兆,李婷,马秀玲,彭素芳,章晨晨。母爱剥夺对成年大鼠行为及多巴胺受体2基因表达的影响[J].中华精神科杂志,2009,42(2)：110-113.
[1]Gilmer WS, McKinney WT. Early experience and depressive disorders:human and non-human primate studies[J]. J Affect Disord,2003,75:97-113.
[2]Tennant C, Smith A, Bebbington P, et al. Parental loss in childhood:relationship to adult psychiatric impairment and contact with psychiatric services[J]. Arch Gen Psychiatry,1981,38:309-314.
[3]Shamseddeen W, Asarnow JR, Clarke G, et al. Impact of physical and sexual abuse on treatment response in the Treatment of Resistant Depression in Adolescent Study (TORDIA[J]). J Am Acad Child Adolesc Psychiatry,2011,50:293-301.
[4]Thakker-Varia S, Alder J. Neuropeptides in depression:role of VGF[J]. Behav Brain Res,2009,197:262-278.
[5]Savitz J, DrevetsWC. Bipolar and major depressive disorder:neuroimaging the developmental-degenerative divide. Neuroscience and biobehavioral reviews [J]. 2009,33(5):699-771.
[6]Kaufman J, Plotsky PM, Nemeroff CB,et al. Effects of early adverse experiences on brain structure and function:clinical implications[J]. Biological Psychiatry,2000,48:778-790.
[7]MacQueen GM, Ramakrishnan K, Ratnasingan R, Chen B, Young LT. Desipramine treatment reduces the long-term behavioural and neurochemical sequelae of early-life maternal separation[J]. Int. J. Neuropsychopharmacol.2003b,6:391-396.
[8]Lippmann M, Bress A, Nemeroff CB, Plotsky PM, Monteggia LM. Long-term behavioural and molecular alterations associated with maternal separation in rats[J]. European Journal of Neuroscience,2007,25:3091-3098.
[9]Macri S, Laviola G. Single episode of maternal deprivation and adult depressive profile in mice:interaction with cannabinoid exposure during adolescence [J]. Behav Brain Res,2004,154:231-238.
[10]Gould E, Gross CG. Neurogenesis in adult mammals:some progress and problems [J]. J Neurosci,2002,22:619-623.
[11]Mirescu C, Gould E. Stress and adult neurogenesis [J]. Hippocampus,2006,16:233-238.
[12]Bremner JD, Narayan M, Anderson ER, et al. Hippocampal volume reduction in major depression[J]. Am J Psychiatry,2000,157:115-118.
[13]Perera TD, Coplan JD, Lisanby SH, et al. Antidepressant-induced neurogenesis in the hippocampus of adult nonhuman primates[J]. J Neurosci,2007,27:4894-4901.
[14]Malberg JE, Eisch AJ, Nestler EJ, et al. Chronic antidepressant treatment increases neurogenesis in adult rat hippocampus [J]. J Neurosci,2000,20:9104-9110.
[15]Santarelli L, Saxe M, Gross C, et al. Requirement of hippocampal neurogenesis for the behavioral effects of antidepressants[J]. Science,2003,301:805-809.
[16]Perera TD, Dwork AJ, Keegan KA, et al. Necessity of hippocampal neurogenesis for the therapeutic action of antidepressants in adult nonhuman primates[J]. PLoS One,2011,6:e17600.
[17]Vythilingam M, Heim C, Newport J, et al. Childhood trauma associated with smaller hippocampal volume in women with major depression[J]. Am J Psychiatry, 2002,159:2072-2080.
[18]Mirescu C, Peters JD, Gould E. Early life experience alters response of adult neurogenesis to stress[J]. Nat Neurosci,2004,7:841-846.
[19]Fabricius K, Wortwein G, Pakkenberg B. The impact of maternal separation on adult mouse behaviour and on the total neuron number in the mouse hippocampus [J]. Brain Struct Funct,2008,212:403-416.
[20]Greisen MH, Altar CA, Bolwig TG, et al. Increased adult hippocampal brain-derived neurotrophic factor and normal levels of neurogenesis in maternal separation rats[J]. J Neurosci Res,2005,79:772-778
[21]Oomen CA, Soeters H, Audureau N, et al. Early maternal deprivation affects dentate gyrus structure and emotional learning in adult female rats[J]. Psychopharmacology (Berl),2011,214:249-260.
[1]McEwen BS. The ever-changing brain:cellular and molecular mechanisms for the effects of stressful experiences[J]. Developmental neurobiology,2012,72(6): 878-890.
[2]Cowansage KK, LeDoux JE, Monfils MH. Brain-derived neurotrophic factor:a dynamic gatekeeper of neural plasticity [J]. Current molecular pharmacology,2010,3(1): 12-29.
[3]Chao MV. Neurotrophins and their receptors; a convergence point for many signalling pathways[J]. Nat Rev Neurosci,2006,4:299-309.
[4]蒋先仲,李云峰,张有志,王乃平.抑郁症与脑内CREB的调节[J].解放军药学学报,2007,23(2)：127-129
[5]Shimizu E.Hashimoto K, Okamura N, et al. Alterations of serum levels of brain-derived neurotrophic factor (BDNF) in depressed patients with or without antidepressants[J]. Biol Psychiatry,2003,54:70-72.
[6]Aydemir C, Yalcin ES, Aksaray S, et al. Brain-derived neurotrophic factor (BDNF) changes in the serum of depressed women[J].Prog Neuropsychopharmacol Biol Psychiatry,2006,30: 1256-1265.
[7]Shaywizt AJ, Greenberg ME. CREB:a stimulus-induced transcription factor activated by adverse array of extracellular signals[J]. Annu Rev Biochem,1999,68:821-826.
[8]Roceri M, Hendriks W, Racagni G, Ellenbroek BA, Riva MA. Early maternal deprivation reduces the expression of BDNF and NMDA receptor subunits in rat hippocampus [J]. Molecular psychiatry,2002,7(6):609-616.
[9]Lippmann M, Bress A, Nemeroff CB, Plotsky PM, Monteggia LM. Long-term behavioural and molecular alterations associated with maternal separation in rats[J]. European Journal of Neuroscience,2007,25:3091-3098.
[10]MacQueen GM, Campbell S, McEwen BS, et al. Course of illness, hippocampal function, and hippocampal volume in major depression [J]. Proc. Natl. Acad. Sci. USA,2003,100:1387-1392.
[11]Kaufman J, Plotsky PM, Nemeroff CB, et al. Effects of early adverse experiences on brain structure and function:clinical implications[J]. Biol. Psychiatr,2000, 48:778-790.
[12]孙奕,张志珺.海马神经元再生及可塑性与抑郁症[J].国际精神病学杂志.2007,34(3)：144-147
[13]Kumaa H, e t a 1. Early maternal deprivation induces Alterations in brain-derived neurotrophic factor expression in the developing rat hippocampus[J]. Neuroscience Letters,2004,372:68-73.
[14]Greisen MH, Altar A, Bolwig TG, et al. Increased Adult Hippocampal Brain-Derived Neurotrophic Factor and Normal Levels of Neurogenesis in Maternal Separation Rats[J]. Journal of Neuroscience Research,2005,79772-778
[1]MacMaster FP, Mirza Y, Szeszko PR, et al. Amygdala and hippocampal volume loss in familial early-onset major depressive disorder[J]. Biol Psychiatry,2008,63: 385-390.
[2]Rao U, Chen LA, Bidesi AS, et al. Hippocampal changes associated with early-life adversity and vulnerability to depression[J]. Biol Psychiatry,2010,67:357-364.
[3]Frodl T, Reinhold E, Koutsouleris N, et al. Childhood stress, serotonin transporter gene and brain structures in major depression[J]. Neuropsycho-pharmacology,2010,35:1383-1390.
[4]Karege F, Perret G, Bondolfi G, Schwald M, Bertschy G, Aubry JM. Decreased serum brain-derived neurotrophic factor levels in major depressed patients[J]. Psychiatry research,2002,109(2):143-148.
[5]Smith MA, Makino S, Kvetnansky R, Post RM. Stress and glucocorticoids affect the expression of brain-derived neurotrophic factor and neurotrophin-3 mRNAs in the hippocampus[J]. J Neurosci,1995,15:1768-1777.
[6]Russo-Neustadt A, Ha T, Ramirez R, Kesslak JP. Physical activity-antidepressant treatment combination:impact on brain-derived neurotrophic factor and behavior in an animal model[J]. Behav Brain Res,2001,120(1):87-95.
[7]Rasmusson AM, Shi L, Duman R. Downregulation of BDNF mRNA in the hippo-campal dentate gyrus after re-exposure to cues previously associated with footshock. Neuropsychopharmacology 2002;27(2):133-42.
[8]Franklin TB, Perrot-Sinal TS. Sex and ovarian steroids modulate brain-derived neurotrophic factor (BDNF) protein levels in rat hippocampus under stressful and non-stressful conditions. Psychoneuroendocrinology 2006;31(1):38-48.
[9]Duman RS. Synaptic plasticity and mood disorders. Mol Psychiatry 2002;7 (Suppl 1):S29-34.
[10]Castren E. Is mood chemistry? Nat Rev Neurosci 2005;6(3):241-6.
[11]Shirayama Y, Chen AC, Nakagawa S, et al. Brain-derived neurotrophic factor produces antidepressant effects in behavioral models of depression. J Neurosci 2002; 22:3251-61
[12]Benn SC, Woolf CJ. Adult neuron survival strategies-slamming on the brakes.Nature Reviews 2004;5:686-700.
[13]Tenant C. Parental loss in childhood relationship to adult psychiatric impairment and contact with psychiatric services[J]. Arch Gen Psychiat,1981, 38(2):309-315.
[14]Shamseddeen W.Asarnow JR,Clarke G,Vitiello B, Wagner KD, Birmaher B, Keller MB, Emslie G, Iyengar S, Ryan ND, McCracken JT, Porta G, Mayes T, Brent DA. Impact of physical and sexual abuse on treatment response in the treatment of resistant depression in adolescent study (TORDIA) [J]. Journal of the American Academy of Child and Adolescent Psychiatry,2011,50(3):293-301.
[15]Lippmann M, Bress A, Nemerof f CB, Plotsky PM, Monteggia LM. Long-term behavioural and molecular alterations associated with maternal separation in rats[J]. European Journal of Neuroscience,2007,25:3091-3098.
[16]Faure J, Uys JDK, Marais L, Stein DJ, Daniels WMU. Early maternal separation alters the response to traumatization:resulting in increased levels of hippocampal neurotrophic factors Neonatal Isolation. Metab Brain Dis,2007, 22:183-195.
[17]Morinobu S, Tsuji S, Takahashi M, Russell DS, Takahashi J, Tanaka K, Fujimaki K, Yamawaki S, Endoh S, Endoh M. Stress Vulnerability Induced by Neonatal Isolation and the Disturbance Between the Phosphorylation and Dephosphorylation of CREB. In Ksto N, PTSD, Brain Mechanisms and Clinical Implications[M]. Tokyo:Springer Japan,2006,37-45.
[1]Kessler RC, Berglund P, Demler O, et al. The epidemiology of major depressive disorder:results from the National Comorbidity Survey Replication (NCS-R) [J]. JAMA,2003,289(23):3095-3105.
[2]Evans E, Hawton K, Rodham K, et al. The prevalence of suicidal phenomena in adolescents:a systematic review of population-based studies[J]. Suicide Life ThreatBehav,2005,35:239-250.
[3]Manji HK, Drevets WC, Chamey DS. The cellular neurobiology of depression[J]. Nat Med 2000,7:541-547.
[4]Ressler KJ, Mayberg KS. Targeting abnormal circuits in mood and anxiety disorders from the laboratory to the clinic[J]. Nat Neurosci,2007,10:1116-1124.
[5]Dwivedi Y. Brain derived neurotrophic factor:a role in depression and suicide [J]. Neuropsychiatr Dis Treat,2009,5:433-439.
[6]Hastings NB,Seth MI, Tanapat P, et al. Granule neurons generated during development extend divergent axon collaterals to hippocampal area CA3[J]. J Comparative Neurol,2002,452:324-333.
[7]Cameron HA, McKay RDG. Adult neurogenesis produces a large pool of granule cells in the dentate gyrus[J]. J Comparative Neurol,2001,435:406-417.
[8]Duman RS, Malberg J, Thome J. Neural plasticity to stress and antidepressant treatment[J]. Biol Psychiatry,1999,46:1181-1191.
[9]Duman RS, Nakagawa S, Malberg J. Regulation of adult neurogenesis by antidepressant treatment[J]. Neuropsychopharmacology,2001,25:836-884.
[10]MacQueen GM, Campbell S, McEwen BS, et al. Course of illness, hippocampal function, and hippocampal volume in major depression[J]. Proc Nati Acad Sei U S A,2003,100:1387-1392.
[11]Sapolsky RM. Depression, antidepressants and the shrinking hippocampus[J]. Proc Nati Acad Sei U S A,2001,98:12320-12322.
[12]Frodl TS, Koutsouleris N, Bottlender R, et al. Depressionrelated variation in brain morphology over 3 years:effeets of stress? [J] Arch Gen Psychiatry,2008, 65:1156-1165.
[13]Banasr M, Hery M, Printemps R, et al. Serotonin-induced increases in adult cell proliferation and neurogenesis are mediated through different and common 5-HT receptor subtypes in the dentate gyms and the subventricular zone[J]-Neuro-psyehopharmacol,2004,29:450-460.
[14]Rao U, Chen LA, Bidesi AS, et al. Hippocampal changes associated with early-life adversity and vulnerability to depression[J]. Biol Psychiatry,2010,67:357-364.
[15]Chen MC, Hamilton JP, Gotlib IH. Decreased hippocampus volume in healthy girls at risk for depression[J].Areh Gen Psychiatry,2010,67:270-276.
[16]Wang JW, David DJ, Monckton JE, et al. Chronic fluoxetine stimulates maturation and synaptic plasticity of adult-bom hippocampal granule cells[J]. J Neurosci, 2008,28(6):1374-1384.
[17]Santarelli L, Saxe M, Gross C, et al. Requirement of hippocampal neurogenesis for the behavioral effects of antidepressants[J]. Science,2003,301:805-809.
[18]Dranovsky A, Hen R. Hippocampal neurogenesis:regulation by stress and antidepressants[J]. Biol Psychiatry,2006,59:1136-1143.
[19]Karl A, Schaefer M, Malta LS, et al. A meta-analysis of structural brain abnormalities in PTSD[J]. Neurosci Biobehav Rev,2006,30:1004-1031.
[20]Coe CL, Kramer M, Czeh B, et al. Prenatal stress diminishes neurogenesis in the dentate gyrus of juvenile Rhesus monkeys [J]. Biol Psychiatry,2003,54:1025-1034.
[21]Czeh B, Michaelis T, Watanabe T, et al. Stress-induced changes in cerebral metabolites, hippocampal volume, and cell proliferation are prevented by antidepressant treatment with tianeptine[J]. Proc Nati Acad Sei U S A,2001,98: 12796-12801.
[22]Hajszan T, Dow A, Warner-Schmidt JL, et al. Remodeling of hippocampal spine synapses in the rat learned helplessness model of depress ion [J]. Biol Psychiatry, 2009,65:392-400.
[23]Kobayashi K, Ikeda Y, Sakai A, et al. Reversal of hippocampal neuronal maturation by serotonergic antidepressants[J]. Proc Nati Acad Sei U S A,2010,107: 8434-8439.
[24]Castren E, Rantamaki T. Role of brain-derived neurotrophic factor in the etiology of depression:implications for pharmacological treatment[J]. CNS Drugs,2010,24:1-7.
[25]Pandey GN, Dwivedi Y, Rizavi HS, et al. Brain-derived neurotrophic factor gene in pediatrie and adult depressed subjects[J]. Prog Neuro-Psychopharmacol Biol Psychiatry,2010,34:645-651.
[26]Sen S, Duman RS, Sanacora G. Serum brain derived neurotrophic factor, depression and antidepressant medications:meta-analyses and implications[J]. Biol Psychiatry,2008,64:527-532.
[27]Luberg K, Wong J, Weickert CS, et al. Human TrkB gene:novel alternative transcripts, protein isomorfs, and expression pattern in the prefrontal cerebral cortex during postnatal development[J]. J Neurochem,2010,113:952-964.
[28]Sairanen M, Lucas G, Emfors P et al. Brain-derived neurotrophic factor and antidepressant drugs have different but coordinated effects on neuronal turn-over, proliferation, and survival in the adult dentate gyrus[J]. J Neurosci,2005,25(5):1089-1094.
[29]Pittenger C, Duman RS. Stress, depression and neuroplasticity:a convergence of mechanisms[J]. Neuropsychopharmacology,2008,33:88-109.
[30]Roceri M, Hendriks W, Racagni G et al. Early maternal deprivation reduces the expression of BDNF and NMDA receptor subunits in rat hippocampus[J]. Mol Psychiatry,2002,7:609-616.
[31]Pizarro JM, Lumley LA, Medina W, et al. Acute social defeat reduces neurotrophin expression in brain cortical and subcortical areas in mice[J]. Brain Res,2004, 1025:10-20.
[32]Fuchikami M, Morinobu S, Kurata A, et al. Single immobilization stress differentially alters the expression profile of transcripts of the brain-derived neurotrophic factor (BDNF) gene and histone acetylation at its promoters in the rat hippocampus[J]. Int J Neuropsychopharmacol,2009,12:73-82.
[33]Shirayama Y, Chen AC, Nakagawa S, et al. Brain-derived neurotrophic factor produces antidepressant effects in behavioral models of depression[J]. J Neurosci,2002,22:3251-3261.
[34]Saarelainen T, Hendolin P, Lucas G, et al. Activation of the TrkB neurotrophin receptor is induced by antidepressant drugs and is required for antidepressant-induced behavioral effects[J]. J Neurosci,2005,25(5):1089-1094.
[35]Schmidt HD, Duman RS. Peripheral BDNF produces antidepressant-like effects in cellular and behavioral models[J]. Neuropsychopharmacol,2010,35:2378-2391.
[36]Groves JO. Is it time to reassess the BDNF hypothesis of depression? [J]Mol Psychiatry,2007,12:1079-1088.
[37]Berton O, McClung CA, Dileone RJ, et al. Essential role of BDNF in the mesolimbic dopamine pathway in social defeat stress[J]. Science,2006,311:864-868.
[38]Dwivedi Y, Rizawi HS, Pandey GN. Antidepressants reverse corticosterone-mediated decrease in BDNF expression:dissociation in regulation of specific exons by antidepressants and corticosterone[J]. Neuroscience,2006,139:1017-1029.
[39]Lee BH, Kim YK. Reduced platelet BDNF in patients with major depression[J]. Prog Neuropsychopharmacol Biol Psychiatry,2009,33:849-853.
[40]Molendijk ML, Bus BA, Spinhoven B, et al. Serum levels of brain-derived neurotrophic factor in major depressivedisorder:state-trait issues, clinical features and pharmacological treatment[J]. Mol Psychiatry, Epub 2010 Sep 21
[41]Aydemir 0, Deveci A, Taneli F. The effect of chronic antidepressant treatment on serum brain-derived neurotrophic factor levels in depressed patients:a preliminary study[J]. Prog Neuropsychopharmacol,2005,29:261-265.
[42]Brunoni AR, Lopes M, Fregni F. A systematic review and meta-analysis of clinical studies on depression and BDNF levels:implications for the role of neuroplasticity in depression[J]. Int J Neuropsychopharmacol,2008,11:1169-1180.
[43]Gould E. How widespread is adult neurogenesis in mammals? [J]Nat Rev Neurosci, 2007,8:481-488.
[44]Jaholkowski P, Kiryk A, Jedynak P, et al. New hippocampal neurons are not obligatory for memory formation; cyclin D2 knockout mice with no adult brain neurogenesis show learning[J]. Learn Mem,2009,16:439-451.
[45]Gadian DG, Aicardi J, Watkins KE, et al. Developmental amnesia associated with early hypoxic-isehaemic injury[J].Brain,2000,123:499-507.
[2]Gilmer WS, McKinney WT.Early experience and depressive disorders:human and non-human primate studies[J]. Journal of affective disorders,2003,75(2): 97-113.
[3]McCauley J, Kern DE Kolodner K, Dill L, Schroeder AF, DeChant HK, Ryden J, Derogatis LR, Bass EB. Clinical characteristics of women with a history of childhood abuse: unhealed wounds[J]. JAMA:the journal of the American Medical Association,1997,277(17):1362-1368.
[4]Tenant C. Parental loss in childhood relationship to adult psychiatric impairment and contact with psychiatric services[J]. Arch Gen Psychiat,1981, 38(2):309-315.
[5]Shamseddeen W, Asarnow JR,Clarke G,Vitiello B,Wagner KD, Birmaher B,Keller MB, Emslie G, Iyengar S, Ryan ND, McCracken JT, Porta G, Mayes T, Brent DA. Impact of physical and sexual abuse on treatment response in the treatment of resistant depression in adolescent study (TORDIA)[J]. Journal of the American Academy of Child and Adolescent Psychiatry,2011,50(3):293-301.
[6]Thakker-Varia S, Alder J. Neuropeptides in depression:Role of VGF[J]. Behavioural brain research,2009,197(2):262-278.
[7]Small SA,Schobel SA, Buxton RB,Witter MP, Barnes CA. A pathophysiological framework of hippocampal dysfunction in ageing and disease [J]. Nature reviews. Neuroscience,2011,12(10):585-601.
[8]Savitz J, DrevetsWC. Bipolar and major depressive disorder:neuroimaging the evelopmental-degenerative divide. Neuroscience and biobehavioral reviews[J].2009,33(5):699-771.
[9]Duman RS, Malberg J, Thome J. Neural plasticity to stress and antidepressant treatment [J]. Biological psychiatry,1999,46(9):1181-1191.
[10]Duman RS, Nakagawa S, Malberg J. Regulation of adult neurogenesis by anti-depressant treatment[J]. Neuropsychopharmacology:official publication of the American College of Neuropsychopharmacology,2001,25(6):836-844.
[11]Perera TD, Dwork AJ, Keegan KA, Thirumangalakudi L, Lipira CM, Joyce N, Lange C, Higley JD,Rosoklija G, Hen R, Sackeim HA, Coplan JD. Necessity of hippocampal neurogenesis for the therapeutic action of antidepressants in adult nonhuman primates [J]. PloS one,2011,6(4):e17600.
[12]Santarelli L, Saxe M, Cross C, Surget A, Battaglia F, Dulawa S, Weisstaub N, Lee J,Duman R, Arancio 0, Belzung C, Hen R. Requirement of hippocampal neurogenesis for the behavioral effects of antidepressants [J]. Science,2003,301 (5634):805-809.
[13]Aydemir C, Yalcin ES, Aksaray S, et al. Brain-derived neurotrophic factor (BDNF) changes in the serum of depressed women[J]. Prog Neuropsychopharmacol Biol Psychiatry,2006,30(7):1256.
[14]Shinizu E, Hashinoto K,Okamura N, et a.l Alterations of serum levels ofbrain-derived neurotrophic factor (BDNF) in depressed patients with or without antidepressants[J]. Biol Psychiatry,2003,54(1):70.
[15]Blendy JA. The role of CREB in depression and antidepressant treatment [J]. Biol Psychiatry,2006,59:1144-1150.
[16]Ru " edi-Bettschen D, Feldon J, Pryce C R. The impaired coping induced by early deprivation is reversed by chronic fluoxetine treatment in adult Fischer rats[J]. BehaviouralPharmacology,2004,15:413-421.
[17]MacQueen GM, Ramakrishnan K, Ratnasingan R, Chen B,Young LT. Desipramine treatment reduces the long-term behavioural and neurochemical sequelae of early-life maternal separation[J]. Int. J. Neuropsychopharmacol.2003b,6: 391-396.
[18]Macri S, Laviola G. Single episode of maternal deprivation and adult depressive profile in mice:interaction with cannabinoid exposure during adolescence [J]. Behav Brain Res,2004,154:231-238.
[19]Lippmann M, Bress A, Nemeroff CB, Plotsky PM, Monteggia LM. Long-term behavioural and molecular alterations associated with maternal separation in rats[J]. European Journal of Neuroscience,2007,25:3091-3098.
[20]朱熊兆,李婷,马秀玲,彭素芳,章晨晨。母爱剥夺对成年大鼠行为及多巴胺受体2基因表达的影响[J].中华精神科杂志,2009,42(2)：110-113.
[1]Gilmer WS, McKinney WT. Early experience and depressive disorders:human and non-human primate studies[J]. J Affect Disord,2003,75:97-113.
[2]Tennant C, Smith A, Bebbington P, et al. Parental loss in childhood:relationship to adult psychiatric impairment and contact with psychiatric services[J]. Arch Gen Psychiatry,1981,38:309-314.
[3]Shamseddeen W, Asarnow JR, Clarke G, et al. Impact of physical and sexual abuse on treatment response in the Treatment of Resistant Depression in Adolescent Study (TORDIA[J]). J Am Acad Child Adolesc Psychiatry,2011,50:293-301.
[4]Thakker-Varia S, Alder J. Neuropeptides in depression:role of VGF[J]. Behav Brain Res,2009,197:262-278.
[5]Savitz J, DrevetsWC. Bipolar and major depressive disorder:neuroimaging the developmental-degenerative divide. Neuroscience and biobehavioral reviews [J]. 2009,33(5):699-771.
[6]Kaufman J, Plotsky PM, Nemeroff CB,et al. Effects of early adverse experiences on brain structure and function:clinical implications[J]. Biological Psychiatry,2000,48:778-790.
[7]MacQueen GM, Ramakrishnan K, Ratnasingan R, Chen B, Young LT. Desipramine treatment reduces the long-term behavioural and neurochemical sequelae of early-life maternal separation[J]. Int. J. Neuropsychopharmacol.2003b,6:391-396.
[8]Lippmann M, Bress A, Nemeroff CB, Plotsky PM, Monteggia LM. Long-term behavioural and molecular alterations associated with maternal separation in rats[J]. European Journal of Neuroscience,2007,25:3091-3098.
[9]Macri S, Laviola G. Single episode of maternal deprivation and adult depressive profile in mice:interaction with cannabinoid exposure during adolescence [J]. Behav Brain Res,2004,154:231-238.
[10]Gould E, Gross CG. Neurogenesis in adult mammals:some progress and problems [J]. J Neurosci,2002,22:619-623.
[11]Mirescu C, Gould E. Stress and adult neurogenesis [J]. Hippocampus,2006,16:233-238.
[12]Bremner JD, Narayan M, Anderson ER, et al. Hippocampal volume reduction in major depression[J]. Am J Psychiatry,2000,157:115-118.
[13]Perera TD, Coplan JD, Lisanby SH, et al. Antidepressant-induced neurogenesis in the hippocampus of adult nonhuman primates[J]. J Neurosci,2007,27:4894-4901.
[14]Malberg JE, Eisch AJ, Nestler EJ, et al. Chronic antidepressant treatment increases neurogenesis in adult rat hippocampus [J]. J Neurosci,2000,20:9104-9110.
[15]Santarelli L, Saxe M, Gross C, et al. Requirement of hippocampal neurogenesis for the behavioral effects of antidepressants[J]. Science,2003,301:805-809.
[16]Perera TD, Dwork AJ, Keegan KA, et al. Necessity of hippocampal neurogenesis for the therapeutic action of antidepressants in adult nonhuman primates[J]. PLoS One,2011,6:e17600.
[17]Vythilingam M, Heim C, Newport J, et al. Childhood trauma associated with smaller hippocampal volume in women with major depression[J]. Am J Psychiatry, 2002,159:2072-2080.
[18]Mirescu C, Peters JD, Gould E. Early life experience alters response of adult neurogenesis to stress[J]. Nat Neurosci,2004,7:841-846.
[19]Fabricius K, Wortwein G, Pakkenberg B. The impact of maternal separation on adult mouse behaviour and on the total neuron number in the mouse hippocampus [J]. Brain Struct Funct,2008,212:403-416.
[20]Greisen MH, Altar CA, Bolwig TG, et al. Increased adult hippocampal brain-derived neurotrophic factor and normal levels of neurogenesis in maternal separation rats[J]. J Neurosci Res,2005,79:772-778
[21]Oomen CA, Soeters H, Audureau N, et al. Early maternal deprivation affects dentate gyrus structure and emotional learning in adult female rats[J]. Psychopharmacology (Berl),2011,214:249-260.
[1]McEwen BS. The ever-changing brain:cellular and molecular mechanisms for the effects of stressful experiences[J]. Developmental neurobiology,2012,72(6): 878-890.
[2]Cowansage KK, LeDoux JE, Monfils MH. Brain-derived neurotrophic factor:a dynamic gatekeeper of neural plasticity [J]. Current molecular pharmacology,2010,3(1): 12-29.
[3]Chao MV. Neurotrophins and their receptors; a convergence point for many signalling pathways[J]. Nat Rev Neurosci,2006,4:299-309.
[4]蒋先仲,李云峰,张有志,王乃平.抑郁症与脑内CREB的调节[J].解放军药学学报,2007,23(2)：127-129
[5]Shimizu E.Hashimoto K, Okamura N, et al. Alterations of serum levels of brain-derived neurotrophic factor (BDNF) in depressed patients with or without antidepressants[J]. Biol Psychiatry,2003,54:70-72.
[6]Aydemir C, Yalcin ES, Aksaray S, et al. Brain-derived neurotrophic factor (BDNF) changes in the serum of depressed women[J].Prog Neuropsychopharmacol Biol Psychiatry,2006,30: 1256-1265.
[7]Shaywizt AJ, Greenberg ME. CREB:a stimulus-induced transcription factor activated by adverse array of extracellular signals[J]. Annu Rev Biochem,1999,68:821-826.
[8]Roceri M, Hendriks W, Racagni G, Ellenbroek BA, Riva MA. Early maternal deprivation reduces the expression of BDNF and NMDA receptor subunits in rat hippocampus [J]. Molecular psychiatry,2002,7(6):609-616.
[9]Lippmann M, Bress A, Nemeroff CB, Plotsky PM, Monteggia LM. Long-term behavioural and molecular alterations associated with maternal separation in rats[J]. European Journal of Neuroscience,2007,25:3091-3098.
[10]MacQueen GM, Campbell S, McEwen BS, et al. Course of illness, hippocampal function, and hippocampal volume in major depression [J]. Proc. Natl. Acad. Sci. USA,2003,100:1387-1392.
[11]Kaufman J, Plotsky PM, Nemeroff CB, et al. Effects of early adverse experiences on brain structure and function:clinical implications[J]. Biol. Psychiatr,2000, 48:778-790.
[12]孙奕,张志珺.海马神经元再生及可塑性与抑郁症[J].国际精神病学杂志.2007,34(3)：144-147
[13]Kumaa H, e t a 1. Early maternal deprivation induces Alterations in brain-derived neurotrophic factor expression in the developing rat hippocampus[J]. Neuroscience Letters,2004,372:68-73.
[14]Greisen MH, Altar A, Bolwig TG, et al. Increased Adult Hippocampal Brain-Derived Neurotrophic Factor and Normal Levels of Neurogenesis in Maternal Separation Rats[J]. Journal of Neuroscience Research,2005,79772-778
[1]MacMaster FP, Mirza Y, Szeszko PR, et al. Amygdala and hippocampal volume loss in familial early-onset major depressive disorder[J]. Biol Psychiatry,2008,63: 385-390.
[2]Rao U, Chen LA, Bidesi AS, et al. Hippocampal changes associated with early-life adversity and vulnerability to depression[J]. Biol Psychiatry,2010,67:357-364.
[3]Frodl T, Reinhold E, Koutsouleris N, et al. Childhood stress, serotonin transporter gene and brain structures in major depression[J]. Neuropsycho-pharmacology,2010,35:1383-1390.
[4]Karege F, Perret G, Bondolfi G, Schwald M, Bertschy G, Aubry JM. Decreased serum brain-derived neurotrophic factor levels in major depressed patients[J]. Psychiatry research,2002,109(2):143-148.
[5]Smith MA, Makino S, Kvetnansky R, Post RM. Stress and glucocorticoids affect the expression of brain-derived neurotrophic factor and neurotrophin-3 mRNAs in the hippocampus[J]. J Neurosci,1995,15:1768-1777.
[6]Russo-Neustadt A, Ha T, Ramirez R, Kesslak JP. Physical activity-antidepressant treatment combination:impact on brain-derived neurotrophic factor and behavior in an animal model[J]. Behav Brain Res,2001,120(1):87-95.
[7]Rasmusson AM, Shi L, Duman R. Downregulation of BDNF mRNA in the hippo-campal dentate gyrus after re-exposure to cues previously associated with footshock. Neuropsychopharmacology 2002;27(2):133-42.
[8]Franklin TB, Perrot-Sinal TS. Sex and ovarian steroids modulate brain-derived neurotrophic factor (BDNF) protein levels in rat hippocampus under stressful and non-stressful conditions. Psychoneuroendocrinology 2006;31(1):38-48.
[9]Duman RS. Synaptic plasticity and mood disorders. Mol Psychiatry 2002;7 (Suppl 1):S29-34.
[10]Castren E. Is mood chemistry? Nat Rev Neurosci 2005;6(3):241-6.
[11]Shirayama Y, Chen AC, Nakagawa S, et al. Brain-derived neurotrophic factor produces antidepressant effects in behavioral models of depression. J Neurosci 2002; 22:3251-61
[12]Benn SC, Woolf CJ. Adult neuron survival strategies-slamming on the brakes.Nature Reviews 2004;5:686-700.
[13]Tenant C. Parental loss in childhood relationship to adult psychiatric impairment and contact with psychiatric services[J]. Arch Gen Psychiat,1981, 38(2):309-315.
[14]Shamseddeen W.Asarnow JR,Clarke G,Vitiello B, Wagner KD, Birmaher B, Keller MB, Emslie G, Iyengar S, Ryan ND, McCracken JT, Porta G, Mayes T, Brent DA. Impact of physical and sexual abuse on treatment response in the treatment of resistant depression in adolescent study (TORDIA) [J]. Journal of the American Academy of Child and Adolescent Psychiatry,2011,50(3):293-301.
[15]Lippmann M, Bress A, Nemerof f CB, Plotsky PM, Monteggia LM. Long-term behavioural and molecular alterations associated with maternal separation in rats[J]. European Journal of Neuroscience,2007,25:3091-3098.
[16]Faure J, Uys JDK, Marais L, Stein DJ, Daniels WMU. Early maternal separation alters the response to traumatization:resulting in increased levels of hippocampal neurotrophic factors Neonatal Isolation. Metab Brain Dis,2007, 22:183-195.
[17]Morinobu S, Tsuji S, Takahashi M, Russell DS, Takahashi J, Tanaka K, Fujimaki K, Yamawaki S, Endoh S, Endoh M. Stress Vulnerability Induced by Neonatal Isolation and the Disturbance Between the Phosphorylation and Dephosphorylation of CREB. In Ksto N, PTSD, Brain Mechanisms and Clinical Implications[M]. Tokyo:Springer Japan,2006,37-45.
[1]Kessler RC, Berglund P, Demler O, et al. The epidemiology of major depressive disorder:results from the National Comorbidity Survey Replication (NCS-R) [J]. JAMA,2003,289(23):3095-3105.
[2]Evans E, Hawton K, Rodham K, et al. The prevalence of suicidal phenomena in adolescents:a systematic review of population-based studies[J]. Suicide Life ThreatBehav,2005,35:239-250.
[3]Manji HK, Drevets WC, Chamey DS. The cellular neurobiology of depression[J]. Nat Med 2000,7:541-547.
[4]Ressler KJ, Mayberg KS. Targeting abnormal circuits in mood and anxiety disorders from the laboratory to the clinic[J]. Nat Neurosci,2007,10:1116-1124.
[5]Dwivedi Y. Brain derived neurotrophic factor:a role in depression and suicide [J]. Neuropsychiatr Dis Treat,2009,5:433-439.
[6]Hastings NB,Seth MI, Tanapat P, et al. Granule neurons generated during development extend divergent axon collaterals to hippocampal area CA3[J]. J Comparative Neurol,2002,452:324-333.
[7]Cameron HA, McKay RDG. Adult neurogenesis produces a large pool of granule cells in the dentate gyrus[J]. J Comparative Neurol,2001,435:406-417.
[8]Duman RS, Malberg J, Thome J. Neural plasticity to stress and antidepressant treatment[J]. Biol Psychiatry,1999,46:1181-1191.
[9]Duman RS, Nakagawa S, Malberg J. Regulation of adult neurogenesis by antidepressant treatment[J]. Neuropsychopharmacology,2001,25:836-884.
[10]MacQueen GM, Campbell S, McEwen BS, et al. Course of illness, hippocampal function, and hippocampal volume in major depression[J]. Proc Nati Acad Sei U S A,2003,100:1387-1392.
[11]Sapolsky RM. Depression, antidepressants and the shrinking hippocampus[J]. Proc Nati Acad Sei U S A,2001,98:12320-12322.
[12]Frodl TS, Koutsouleris N, Bottlender R, et al. Depressionrelated variation in brain morphology over 3 years:effeets of stress? [J] Arch Gen Psychiatry,2008, 65:1156-1165.
[13]Banasr M, Hery M, Printemps R, et al. Serotonin-induced increases in adult cell proliferation and neurogenesis are mediated through different and common 5-HT receptor subtypes in the dentate gyms and the subventricular zone[J]-Neuro-psyehopharmacol,2004,29:450-460.
[14]Rao U, Chen LA, Bidesi AS, et al. Hippocampal changes associated with early-life adversity and vulnerability to depression[J]. Biol Psychiatry,2010,67:357-364.
[15]Chen MC, Hamilton JP, Gotlib IH. Decreased hippocampus volume in healthy girls at risk for depression[J].Areh Gen Psychiatry,2010,67:270-276.
[16]Wang JW, David DJ, Monckton JE, et al. Chronic fluoxetine stimulates maturation and synaptic plasticity of adult-bom hippocampal granule cells[J]. J Neurosci, 2008,28(6):1374-1384.
[17]Santarelli L, Saxe M, Gross C, et al. Requirement of hippocampal neurogenesis for the behavioral effects of antidepressants[J]. Science,2003,301:805-809.
[18]Dranovsky A, Hen R. Hippocampal neurogenesis:regulation by stress and antidepressants[J]. Biol Psychiatry,2006,59:1136-1143.
[19]Karl A, Schaefer M, Malta LS, et al. A meta-analysis of structural brain abnormalities in PTSD[J]. Neurosci Biobehav Rev,2006,30:1004-1031.
[20]Coe CL, Kramer M, Czeh B, et al. Prenatal stress diminishes neurogenesis in the dentate gyrus of juvenile Rhesus monkeys [J]. Biol Psychiatry,2003,54:1025-1034.
[21]Czeh B, Michaelis T, Watanabe T, et al. Stress-induced changes in cerebral metabolites, hippocampal volume, and cell proliferation are prevented by antidepressant treatment with tianeptine[J]. Proc Nati Acad Sei U S A,2001,98: 12796-12801.
[22]Hajszan T, Dow A, Warner-Schmidt JL, et al. Remodeling of hippocampal spine synapses in the rat learned helplessness model of depress ion [J]. Biol Psychiatry, 2009,65:392-400.
[23]Kobayashi K, Ikeda Y, Sakai A, et al. Reversal of hippocampal neuronal maturation by serotonergic antidepressants[J]. Proc Nati Acad Sei U S A,2010,107: 8434-8439.
[24]Castren E, Rantamaki T. Role of brain-derived neurotrophic factor in the etiology of depression:implications for pharmacological treatment[J]. CNS Drugs,2010,24:1-7.
[25]Pandey GN, Dwivedi Y, Rizavi HS, et al. Brain-derived neurotrophic factor gene in pediatrie and adult depressed subjects[J]. Prog Neuro-Psychopharmacol Biol Psychiatry,2010,34:645-651.
[26]Sen S, Duman RS, Sanacora G. Serum brain derived neurotrophic factor, depression and antidepressant medications:meta-analyses and implications[J]. Biol Psychiatry,2008,64:527-532.
[27]Luberg K, Wong J, Weickert CS, et al. Human TrkB gene:novel alternative transcripts, protein isomorfs, and expression pattern in the prefrontal cerebral cortex during postnatal development[J]. J Neurochem,2010,113:952-964.
[28]Sairanen M, Lucas G, Emfors P et al. Brain-derived neurotrophic factor and antidepressant drugs have different but coordinated effects on neuronal turn-over, proliferation, and survival in the adult dentate gyrus[J]. J Neurosci,2005,25(5):1089-1094.
[29]Pittenger C, Duman RS. Stress, depression and neuroplasticity:a convergence of mechanisms[J]. Neuropsychopharmacology,2008,33:88-109.
[30]Roceri M, Hendriks W, Racagni G et al. Early maternal deprivation reduces the expression of BDNF and NMDA receptor subunits in rat hippocampus[J]. Mol Psychiatry,2002,7:609-616.
[31]Pizarro JM, Lumley LA, Medina W, et al. Acute social defeat reduces neurotrophin expression in brain cortical and subcortical areas in mice[J]. Brain Res,2004, 1025:10-20.
[32]Fuchikami M, Morinobu S, Kurata A, et al. Single immobilization stress differentially alters the expression profile of transcripts of the brain-derived neurotrophic factor (BDNF) gene and histone acetylation at its promoters in the rat hippocampus[J]. Int J Neuropsychopharmacol,2009,12:73-82.
[33]Shirayama Y, Chen AC, Nakagawa S, et al. Brain-derived neurotrophic factor produces antidepressant effects in behavioral models of depression[J]. J Neurosci,2002,22:3251-3261.
[34]Saarelainen T, Hendolin P, Lucas G, et al. Activation of the TrkB neurotrophin receptor is induced by antidepressant drugs and is required for antidepressant-induced behavioral effects[J]. J Neurosci,2005,25(5):1089-1094.
[35]Schmidt HD, Duman RS. Peripheral BDNF produces antidepressant-like effects in cellular and behavioral models[J]. Neuropsychopharmacol,2010,35:2378-2391.
[36]Groves JO. Is it time to reassess the BDNF hypothesis of depression? [J]Mol Psychiatry,2007,12:1079-1088.
[37]Berton O, McClung CA, Dileone RJ, et al. Essential role of BDNF in the mesolimbic dopamine pathway in social defeat stress[J]. Science,2006,311:864-868.
[38]Dwivedi Y, Rizawi HS, Pandey GN. Antidepressants reverse corticosterone-mediated decrease in BDNF expression:dissociation in regulation of specific exons by antidepressants and corticosterone[J]. Neuroscience,2006,139:1017-1029.
[39]Lee BH, Kim YK. Reduced platelet BDNF in patients with major depression[J]. Prog Neuropsychopharmacol Biol Psychiatry,2009,33:849-853.
[40]Molendijk ML, Bus BA, Spinhoven B, et al. Serum levels of brain-derived neurotrophic factor in major depressivedisorder:state-trait issues, clinical features and pharmacological treatment[J]. Mol Psychiatry, Epub 2010 Sep 21
[41]Aydemir 0, Deveci A, Taneli F. The effect of chronic antidepressant treatment on serum brain-derived neurotrophic factor levels in depressed patients:a preliminary study[J]. Prog Neuropsychopharmacol,2005,29:261-265.
[42]Brunoni AR, Lopes M, Fregni F. A systematic review and meta-analysis of clinical studies on depression and BDNF levels:implications for the role of neuroplasticity in depression[J]. Int J Neuropsychopharmacol,2008,11:1169-1180.
[43]Gould E. How widespread is adult neurogenesis in mammals? [J]Nat Rev Neurosci, 2007,8:481-488.
[44]Jaholkowski P, Kiryk A, Jedynak P, et al. New hippocampal neurons are not obligatory for memory formation; cyclin D2 knockout mice with no adult brain neurogenesis show learning[J]. Learn Mem,2009,16:439-451.
[45]Gadian DG, Aicardi J, Watkins KE, et al. Developmental amnesia associated with early hypoxic-isehaemic injury[J].Brain,2000,123:499-507.