青少期社会隔离和不确定性应激对大鼠成年后情绪行为的影响

目的 分别观察青少期社会隔离和不确定性应激对大鼠成年后情绪行为的影响.方法在青少期(出生后28 d～41 d)分别给予研究组大鼠2周社会隔离应激或不确定性复合应激,应激后经3周恢复至所有大鼠进入成年期后检测其情绪行为改变.采用糖水偏好测试和强迫游泳检测大鼠的抑郁样行为,采用旷场试验和高架十字迷宫试验检测焦虑样行为.结果 与群养组相比,青少期社会隔离组大鼠成年后的所检测的各项情绪行为均无明显差异(P>0.05).经历青少期不确定性应激的成年大鼠与其对照组相比糖水偏好指数没有明显改变[(0.86±0.19) vs (0.86±0.03),P>0.05],但在强迫游泳测试中表现出更多的绝望行为(强迫游泳不动行为增加)[(29.88±3.37) vs (19.90±3.19),P<0.05]、更少的主动行为(挣扎行为减少)[(24.00±1.67) vs (32.90±3.09),P<0.05],提示该应激并不影响大鼠成年后偏好糖水的本能行为,但导致其急性应激应对能力受损,对成年应激事件更容易发展出次级的应对无能或绝望的抑郁样行为.不确定性应激研究组的大鼠成年后在高架十字迷宫测试中较其对照组闭合臂停留时间明显增加[(176.90±17.01) vs (136.48±9.47),P<0.05]以及开放臂进入次数明显减少[(3.00±0.93) vs (5.90±1.08),P<0.05],提示该应激增加了大鼠成年后的焦虑样行为水平.结论 青少期社会隔离应激和不确定性应激对大鼠成年后情绪行为的影响存在差异,青少期不确定性应激能够有效诱导大鼠多项情绪行为显著和持续的改变,提供了一种青少期应激增加成年大鼠应激性抑郁易感性的动物模型.     

高脂诱导肥胖小鼠焦虑表型的评价

目的：研究高脂食物诱导肥胖小鼠的焦虑样行为。方法将12只C57BL／6J雌性小鼠随机分为2组,分别喂养高脂食物及普通食物8周,观察小鼠的体质量变化,用高架十字迷宫、黑白箱、新物体刺激实验测定动物的行为。结果模型组小鼠在高架十字迷宫、黑白箱、新物体刺激实验中均有明显的焦虑表现。结论高脂食物可作为一种诱导肥胖伴焦虑小鼠模型的造模方式,为进一步研究两者之间的关系提供工具支持。     

氟西汀和丙米嗪对应激诱导的青幼期大鼠抑郁和焦虑样行为的不同影响

目的建立青幼期大鼠的慢性应激抑郁模型,并探讨不同类型抗抑郁药物对其抑郁和焦虑样行为表现的影响。方法青幼期大鼠(日龄30～50d)接受3周慢性温和应激,同时随机分别给予选择性5-羟色胺重摄取抑制剂氟西汀和三环类抗抑郁剂丙米嗪(10mg/kgi.p.)。采用蔗糖水偏好、旷场和高架十字迷宫测试评估大鼠的抑郁和焦虑样行为。结果与对照组(n=10)相比,慢性应激模型组(n=11)大鼠体质量增长减慢,糖水偏好指数降低,上述差异均有统计学意义(P0.05)。丙米嗪干预组(n=10)的糖水偏好明显低于丙米嗪对照组(n=10),差异有统计学意义(P0.05),而氟西汀干预组(n=11)与氟西汀对照组(n=11)相比则没有明显差异(P0.05)。在旷场测试中,青幼期后期(PND52)正常对照组大鼠与其早期(PND29)相比旷场直立行为次数降低(P0.05),但自发活动量(水平运动距离)没有明显差异(P0.05),氟西汀干预明显增加大鼠直立行为次数(P0.05)。此外,PND52正常对照组大鼠与PND29相比在高架十字迷宫开放臂的进入次数和停留时间减少,而在闭合臂停留时间增加;应激模型组与正常对照组相比开放臂进入次数增加,闭合臂停留时间减少,上述差异均有统计学意义(P0.05)。结论慢性应激诱导了青幼期大鼠的抑郁样行为。氟西汀而非丙米嗪可逆转大鼠的抑郁样行为。应激降低了青幼期大鼠的焦虑水平,而两种药物对焦虑行为均没有明显作用。     

间歇性酒精暴露对青少年期小鼠酒精犒赏及焦虑行为的影响

目的探讨间歇性酒精暴露(adolescent intermittent ethanol exposure,AIE)对青少年期小鼠酒精条件性位置偏爱(conditioned place preference,CPP)及焦虑行为的影响。方法 4周龄C57BL/6小鼠随机分为2组,每组10只,AIE组接受间歇性酒精腹腔注射(3 g/kg,25%酒精,共8次),NS组接受生理盐水腹腔注射;随后2组行酒精CPP实验(2 g/kg,20%酒精)。另取一批小鼠经高架十字迷宫(elevated plus maze,EPM)测试后,根据开放臂时间比分为高、低焦虑组,各组中再分别随机分为AIE组、NS组,每组8～10只,分别接受间歇性酒精或生理盐水腹腔注射。之后,4组小鼠再次行EPM测试。结果第1项实验中,与NS组相比,AIE组小鼠的CPP值较高[(116.1±12.9)s vs.(70.8±14.8)s,P=0.035]。第2项实验,高、低焦虑小鼠经AIE处理后,分别与高、低焦虑NS组相比,开放臂时间比差异无统计学意义(均P0.05)。结论 AIE促进青少年期小鼠酒精CPP的形成,但不改变其焦虑水平,AIE对小鼠酒精CPP的促进作用与焦虑无关。     

氟西汀对DISC1转基因小鼠应激后抑郁和焦虑样 行为的影响

目的 探讨氟西汀对双重应激诱导的精神分裂症断裂基因1（DISC1）转基因小鼠抑郁和焦 虑样行为的影响。方法 C57BL/6野生型新生小鼠及C57BL/6 LBD-DISC1转基因新生小鼠各16只，分别 随机分为野生应激组、野生对照组和DISC1应激组、DISC1对照组，每组8只。应激组小鼠进行母婴分离 和慢性不可预知轻度应激后，4组小鼠使用氟西汀治疗4周，采用糖水消耗实验、强迫游泳实验及旷场实 验测定小鼠行为。结果 氟西汀治疗后各组小鼠旷场实验中心区域移动距离和强迫游泳静止时间之间 的差异无统计学意义，DISC1应激组的糖水偏好度和体重仍偏低（P＜ 0.01）。结论 氟西汀可改善双重应 激诱导的DISC1转基因小鼠的抑郁和焦虑情绪，但不能缓解其快感缺乏和体重降低。     

地卓西平马来酸盐对抑郁大鼠行为学和前额叶BDNF表达的影响

目的观察地卓西平马来酸盐(MK-801)预处理对利血平诱导的抑郁模型大鼠抑郁行为的改善作用及大脑前额叶脑源性神经营养因子(BDNF)表达的影响。方法采用随机数字表法将32只成年雄性SD大鼠分为4组:对照组、利血平模型组、MK-801+利血平组和MK-801组,每组8只。MK-801+利血平组和MK-801组预先给予腹腔注射MK-801(0.3 mg/kg),对照组和利血平模型组腹腔注射相应体积的生理盐水。30 min后,利血平模型组和MK-801+利血平组腹腔注射利血平(4 mg/kg),对照组和MK-801组腹腔注射相同体积的乙酸溶剂。注射利血平48 h后利用强迫游泳实验观察大鼠的抑郁样行为表现,并在行为实验完成后处死大鼠,以酶联免疫吸附实验(ELISA)检测大脑前额叶BDNF的表达水平。结果在强迫游泳实验中,利血平模型组强迫游泳不动时间[(49.38±7.85)s]长于对照组[(15.59±5.43)s],差异有统计学意义(t=11.91,P0.01);MK-801+利血平组强迫游泳不动时间[(12.32±4.25)s]短于利血平模型组,差异有统计学意义(t=13.06,P0.05)。ELISA结果显示,利血平模型组前额叶BDNF表达水平[(10.09±0.88)ng/mL]低于对照组[(13.29±1.10)ng/mL],差异有统计学意义(t=6.44,P0.01);MK-801+利血平组大鼠前额叶的BDNF表达水平[(12.56±1.83)ng/mL]高于利血平模型组,差异有统计学意义(t=3.44,P0.05)。结论 MK-801可改善大鼠的抑郁样行为,其机制可能与调节脑内BDNF的表达有关。     

电针对慢性不可预知温和应激小鼠模型抑郁样行为及肠道菌群的调节作用

目的 观察电针对慢性不可预知温和应激（CUMS）模型小鼠抑郁样行为及肠道菌群组 成的影响。方法 将 40 只雄性 C57BL/6 小鼠随机分为对照组、电针组、模型组（CUMS 组）和治疗组 （CUMS+ 电针组）,每组 10 只。CUMS 组和 CUMS+ 电针组均接受 CUMS 造模,造模结束后,给予对照组和 CUMS 组小鼠假刺激 7 d,给予电针组和 CUMS+ 电针组小鼠 2/15 Hz、1.0 mA 的电针刺激 7 d。最后一次 干预结束 24 h 后,收集粪便保存在 -80℃条件下并对小鼠进行糖水偏好实验、旷场实验和强迫游泳实 验。对 4 组小鼠的粪便进行 16S rDNA 测序,采用操作分类单元（OTU）信息进行 α 多样性和 β 多样性 分析、线性判别分析效应量分析（LEfSe）。采用 Spearman 相关性分析小鼠行为学指标与差异菌群富集 水平之间的相关性。结果 CUMS 组小鼠的旷场中心区域探索时间短于对照组［（22.058±4.148）s 比 （37.864±4.407）s］,糖水偏好率低于对照组［（53.427±14.550）% 比（76.514±15.701）%］,强迫游泳不动 时间长于对照组［（82.599±32.369）s 比（47.606±15.344）s］,差异有统计学意义（P＜ 0.01）。CUMS+ 电针 组小鼠的旷场中心区域探索时间长于 CUMS 组［（30.604±6.060）s 比（22.058±4.148）s］,糖水偏好率高于 CUMS组［（72.731±13.933）%比（53.427±14.550）%］,强迫游泳不动时间短于CUMS组［（53.633±17.933）s 比（82.599±32.369）s］,差异有统计学意义（P＜ 0.05）。CUMS 组小鼠肠道菌群的 OTU 数量、ACE 指数和 Chao 指数低于对照组,差异有统计学意义（P＜ 0.05）;但 CUMS+ 电针组与 CUMS 组比较,差异无统计学 意义（P＞ 0.05）。Ruminococcaceae_UCG_002 属、蓝绿藻菌属（Lachnoclostridium）和 Rikenellaceae_RC9_ gut_group 属在 CUMS 组中富集,且与抑郁样行为呈正相关（P＜ 0.05）;放线菌门和理研菌属、杜氏杆菌属、 Ileibacterium 属、双歧杆菌属和异杆菌属在电针和 CUMS+ 电针组中富集,且均与抑郁样行为呈负相关 （P＜ 0.05）。结论 电针干预可以缓解小鼠的抑郁样行为,且对其肠道菌群组成有调节作用。     

大鼠出生后不同时期使用氟西汀对体质量和行为远期影响的初步研究

目的 探讨大鼠出生后不同时期使用氟西汀对其体质量和行为的远期影响.方法 随机选择雄性SPrague-Dawley大鼠,在其出生后1～7 d、8～21 d分别皮内注射氟西汀(浓度2 g/L,注射剂量5 ml/kg体质量)(F1组,22只;F2组,20只)和生理盐水(0.9%NaCl,注射剂量5 ml/kg体质量)(S1组,20只;S2组,19只),并追踪观察4组大鼠体质量;大鼠成年后(出生后第90天)进行行为学检测,包括旷场实验、高架十字迷宫、新奇抑制摄食和强迫游泳实验.结果 (1)F1组大鼠体质量的增加延缓,出生后第25天,F1组体质量[(35.5±3.4)g]于S1组[(43.0±3.9)g],至出生后第90天,F1组体质量[(190.7±12.1)g]均小于S1组[(208.0±13.5)g]和F2组[(218.3±14.6)g](两样本t检验,P＜0.05).(2)幼鼠早期使用氟西汀,成年后探索性行为减少,F1组旷场行为总行程[(18.9±2.3)m]明显小于S1组[(38.9±8.1)m],F2组[(33.3±6.2)m]于S2组[(43.7±6.2)m];高架十字迷宫总穿臂次数F1组[(13.8±3.2)次]少于S1组[(37.6±6.3)次],F2组[(32.3±7.1)次]少于S2组[(57±7.3)次](两样本t检验,P＜0.05);焦虑抑郁相关行为增加,新奇抑制摄食潜伏期F1组[(432.2±45.4)s]长于S1组[(167.7±20.3)s],F2组[(270.2±27.2)s]长于S2组[(185.3±19.2)s];强迫游泳静止不动时间百分比F1组[(41.2±3.2)%]长于S1组[(26.5±2.3)%],F2组[(35.1±3.6)%]长于S2组[(27.8±2.5)%](两样本t检验,P＜0.05);且F1组大鼠的异常行为重于F2组(两样本t检验,P＜0.05).结论 幼鼠出生后早期使用氟西汀可导致大鼠体质量增加延缓,成年后出现焦虑抑郁行为,使用氟西汀越早风险越大.     

自主跑笼运动对SAMP8小鼠精神行为及血清促肾上腺皮质激素、皮质醇的影响

目的观察自主跑笼运动对快速老化P8小鼠精神行为学及血清促肾上腺皮质激素(ACTH和皮质醇(Cor)水平的影响。方法雄性3月龄快速老化P8小鼠20只,随机数字表法分为运动组和非运动组,每组10只;抗快速老化R1小鼠5只为对照组。所有小鼠均给予同样标准环境饲养,运动组施加自主跑笼运动训练(每周5天)。2月后采用自主活动仪和高架十字迷宫行为学测试评估小鼠精神行为学变化,同时放射免疫方法检测小鼠血清ACTH及Cor水平。结果快速老化P8小鼠非运动组与同月龄抗快速老化R1小鼠对照组比较,自主活动次数(104.4±33.3,150.0±39.9)和高架十字迷宫开放臂停留时间(157.1±44.9,202.8±39.2)均显著减少(P0.05)。快速老化P8小鼠自主活动次数运动组(159.6±66.6)与非运动组(104.4±33.3)比较显著增加(P0.05);高架十字迷宫测试开放臂停留时间运动组(173.6±51.4)与非运动组(157.1±44.9)比较,差异无统计学意义(P0.05)。快速老化P8小鼠非运动组与抗快速老化R1小鼠对照组比较,血清ACTH(28.49±8.24,47.86±9.52)及Cor水平(3.19±0.88,5.01±0.79)均显著减少(P0.05)。快速老化P8小鼠运动组(50.35±6.64,5.23±1.42)较非运动组(28.49±8.24,3.19±0.88)均显著增高(P0.05)。结论 5月龄快速老化P8小鼠有明显精神行为异常,自主跑笼运动对快速老化P8小鼠精神行为异常有一定改善,可能是通过上调下丘脑-垂体-肾上腺轴活性而实现的。     

不同环境对快速老化雄性小鼠抑郁与焦虑情绪的影响

目的观察不同环境对阿尔茨海默病模型SAMP8快速老化雄性小鼠抑郁、焦虑情绪的影响。方法雄性3月龄SAMP8小鼠30只,称量体质量后随机分为3组,每组各10只。3组小鼠分别在标准环境、丰富环境和贫瘠环境中饲养8周,每周称量各组小鼠体质量并记录其生活状态,8周后采用自主活动和高架十字迷宫实验检测其行为学变化。结果 丰富环境中生活的SAMP8鼠群生活更为和谐,动物间活动和互动现象较多;贫瘠环境中生活的小鼠存在咬伤、死亡现象。8周末3组间体质量差异无统计学意义(P0.05)。对于小鼠的自主活动次数和开放臂停留时间,丰富环境组与标准环境组之间无统计学差异(P0.05);贫瘠环境组与标准环境组之间差异有统计学意义(P0.01)。结论 丰富环境使SAMP8雄性小鼠生活活跃、鼠间交流增多,但尚不能认为其对焦虑、抑郁情绪产生影响。贫瘠环境使SAMP8雄性小鼠活动力下降,焦虑、抑郁症状加重。     

Infralimbic D1 receptor agonist effects on spontaneous novelty exploration and anxiety-like defensive responding in CD-1 mice

Mesocortical dopamine (DA) terminals in the ventromedial prefrontal cortex (vmPFC) integrate cognitive/emotional processing functions underlying adaptive and appropriate behavioral responding to stressful environmental events. Results from several studies have also shown that stressor-enhanced prefrontal DA activation exerts detrimental effects on cognitive performance. However, questions have arisen as to whether stressor-enhanced vmPFC DA transmission exerts direct control over conditioned or unconditioned responses to threatening events, or whether enhanced prefrontal DA transmission gates cognitive processing to facilitate adaptive responding in threatening situations. We have previously shown that infralimbic (IL) vmPFC dopamine D2 agonist and antagonist drug infusions reduced anxiety-like responding in the elevated plus-maze (EPM) and disrupted spontaneous exploration in the Y-maze in CD-1 mice. In the present study, the effects of IL vmPFC infusions of the specific D1 receptor agonist, SKF-81297, in CD-1 mice were evaluated on spontaneous exploration in the Y-maze, anxiety-like responding in a 2-trial elevated plus-maze procedure, and anti-predator defensive responding in the Mouse Defense Test Battery (MDTB). SKF-81297 infusions disrupted spontaneous alternation performance along with potentiated repetitive 2-arm responding in the Y-maze. In the elevated plus-maze, pre-trial 1 IL SKF-81297 infusions reduced anxiety-like responding (enhanced open arm entries and time ratio, unprotected stretch attends and head dips), and reduced closed arm time ratio and protected risk assessment activity (protected stretch attends). In trial 2, 24h later (no drug infusions), open arm entries, open time ratio, and unprotected head dips remained enhanced relative to trial 2 vehicle controls. In the MDTB, avoidance distance was enhanced in the approach test; risk assessment (approach) was enhanced in the closed alley test; and defensive threat (upright postures) was enhanced in the forced contact test. Results are discussed with respect to possible influences of IL vmPFC DA receptors on cognitively mediated responding to differing levels of threat in mice.     

Ontogeny of fear-, anxiety- and depression-related behavior across adolescence in C57BL/6J mice

Adolescence is characterized by behavioral traits such as emotional lability and impulsivity that are associated with increased vulnerability to affective illness and addictions. Research in rodents has found that adolescent rats and mice differ from adults on measures of anxiety-like behavior, novelty seeking and stress-responsivity. The present study sought to extend these data by evaluating fear-, anxiety- and depression-related behaviors in male C57BL/6J mice aged four (early adolescent), six (peri-adolescent) or eight (early adult) weeks of age. Age groups were compared on: Pavlovian fear conditioning and extinction, anxiety-like behavior and exploratory locomotion (using elevated plus-maze and novel open field), and depression-related behavior (via forced swim test). Results showed that early adolescent mice exhibited enhanced fear conditioning, but extinguished at a similar rate as adults. There were no major differences in anxiety-like behavior across age groups, although early adolescent and peri-adolescent mice exhibited less exploratory locomotion than adults. Depression-related immobility behavior in the forced swim test was lower in early adolescents than adult mice across three test exposures. Present findings in the C57BL/6J inbred strain add to growing evidence of changes in rodent fear- and stress-related behaviors across the developmental transition from juvenility through adulthood. Understanding the neural basis of these ontogenic changes could provide insight into the pathogenesis and treatment of affective disorders that have their origins in adolescence.     

Relative age effect and left-handedness in world class water polo male and female players

Most studies of the relative age effect (RAE) refer to popular sports. In contrast, we examined to what extent the RAE is present in elite water polo players, as well as the association between handedness and RAE. For these purposes, laterality, anthropometry, month of birth, performance and playing position of participants in the 2011, 2013 and 2015 World Championships (623 women, 622 men) were analised. No RAE was observed in the total sample. However, the proportion of male left-handed field players born in the first quarter (11%) was lower than those born in the second (35.3%) and fourth quarter (29.4%). Regarding the overall laterality, the amount of left handed players was similar to the general population (10%). Nevertheless, there was a larger amount of left-handed wings than expected both in men (23.7%) and women (34.4%). Left-handed male players performed more shots, shots/minute and also scored more goals than right-handed players. Women left-handed players were younger and they performed more shots/minute. There is no RAE in elite male and female water polo players. However, laterality could be a possible moderator of the RAE particularly in left handed players, which should be taken into account in future studies.     

Right- and left-handed dentists in periodontal therapy

The purpose of this study was to determine whether successful dental therapy (scaling and root planing) depends upon handedness of dentists in right-handed dental chairs (units) Participants were 28 voluntary dentists (14 female and 14 male, ranging in age from 26 to 34 years). Patients (7 female and 7 male with a mean age of 39.6 years) had advanced periodontitis. Handedness was assessed using the Turkish version of the Edinburgh Handedness Inventory. There were two equal groups of dentists: left-handers (7 female, 7 male) and right-handers (7 female, 7 male). Initial examination of patients was performed using a pressure-controlled periodontal probe. During scaling and root planing, the negative interstroke forces were recorded using a piezo-electric receiver, an electronic transducer, and an analogue writer. The results showed that during scaling, mean negative forces reached a mean of 0.74 N in left-handed dentists and 0.52 N in right-handed dentists. During root planing, these forces were 0.86 N in left-handed dentists, and 0.63 N in right-handed dentists. These differences were statistically significant. The right-handed dentists were more successful than the left-handed dentists at scaling and root planing, provided that both of them used the same right-sided dental chairs. The importance of handedness of the dentists was accentuated in dental practice.     

Correlations between behaviours in the elevated plus-maze and sensitivity to unpredictable subchronic mild stress: evidence from inbred strains of mice

This study aimed at investigating the relationship between anxiety-like and depressive-like behaviour in mice. Therefore, we assessed the behaviour of mice from eight different strains (FVB/NA, BALB/c, C57BL/6, DBA/2, 129/Sv, C3H/He, CBA and BA) confronted first to anxiety models (the elevated plus-maze and the free exploratory test) and then to tests of depressive-like behaviours (forced swim test and unpredictable subchronic mild stress). In the forced swim test, mice from the DBA/2, the BA and the C3H/He strains displayed higher immobility than mice from the 129/Sv, the BALB/c, the C57BL/6 and the CBA strains. In the subchronic mild stress, mice from the C57BL/6 and the CBA strains displayed low sensitivity when compared with mice from all the others strains. A stepwise multiple regression analysis suggests that behaviour in the elevated plus-maze is associated with the time of immobility in the forced swim test (20%) and with the susceptibility to the unpredictable subchronic stress procedure (31%). The behaviour in the free exploratory paradigm is slightly associated with behaviours in the two tests of depression. These results suggest that anxiety may be a factor contributing, among others, to the susceptibility to depressive-like behaviours.     

Behavioural characterisation of transgenic mice overexpressing galanin under the PDGF-B promoter

The behavioural phenotype of transgenic mice (3-5-months old) overexpressing galanin (GalOE mice) under the platelet-derived growth factor B (PDGF-B) promoter was evaluated in a battery of tests, including locomotor cages, light-dark exploration test, elevated plus-maze and the Porsolt forced swim test. Learning and memory were assessed in the Morris water maze task. GalOE mice showed a slight increase in spontaneous locomotor activity assessed in the locomotor cages, but the amphetamine-induced increase in locomotor activity was somewhat lower in GalOE mice. Anxiety-like behaviour in light-dark exploration and elevated plus-maze tests did not differ between genotypes. In the Porsolt forced swim test, GalOE mice displayed an increased time of immobility, indicative of increased learned helplessness possibly reflecting increased stress-susceptibility and/or depression-like behaviour. GalOE mice showed normal learning and memory retention in the Morris water maze tasks. These data support the hypothesis that galanin may have a role in functions related to mood states, including affective disorders.     

The rate of handedness conversion and related factors in left-handed children

The rate of handedness conversion was 2.7% to 11.8% in prior studies based on the total population including innately right-handed people. However, the conversion rate of innately left-handed people has not been reported. The purpose of this study was to investigate the percentage of handedness conversion in children who are innately left-handed. The data in the present study showed that 59.3% (121/211) of left-handed children had been forced to convert to right-handedness. Current handedness was also reported by 114 of the 121 informants, and the rates of right-, left-, and mixed-handedness were 56.1% (64/114), 26.3% (30/114), and 17.5% (20/114) respectively. More than half had successfully changed from left to right. Some variables, especially the educational level of the parents and the child's grade level, were related to this conversion intention. The children whose parents had less education were more likely to be forced to change handedness. Additionally, the rate of handedness conversion in younger children was lower than in older children. However, even for the children whose parents had higher education, or for the children who were younger, there was a high percentage (45.7% and 41.8% respectively) who had changed their handedness. Therefore, preventing the possible side effects for children who have undergone hand conversion should be emphasised in the future.     

Strain-dependent effects of prenatal maternal immune activation on anxiety- and depression-like behaviors in offspring

There is converging evidence that prenatal maternal infection can increase the risk of occurrence of neuropsychiatric disorders like schizophrenia, autism, anxiety and depression in later life. Experimental studies have shown conflicting effects of prenatal maternal immune activation on anxiety-like behavior and hypothalamic–pituitary–adrenal (HPA) axis development in offspring. We investigated the effects of maternal immune activation during pregnancy on anxiety- and depression-like behaviors in pregnant mice and their offspring to determine whether these effects are dependent on strain. NMRI and C57BL/6 pregnant mice were treated with either saline or lipopolysaccharide on gestational day 17 and then interleukin (IL)-6 and corticosterone (COR) levels; anxiety or depression in the pregnant mice and their offspring were evaluated. The results indicate that maternal inflammation increased the levels of COR and anxiety-like behavior in NMRI pregnant mice, but not in C57BL/6 dams. Our data also demonstrate that maternal inflammation elevated the levels of anxiety-and depression-like behaviors in NMRI offspring on the elevated plus-maze, elevated zero-maze, tail suspension test and forced swimming test respectively, but not in the open field and light–dark box. In addition, we did not find any significant change in anxiety- and depression-like behaviors of adult C57BL/6 offspring. Our findings suggest that prenatal maternal immune activation can alter the HPA axis activity, anxiety- and depression-like behaviors in a strain- and task-dependent manner in offspring and further comprehensive studies are needed to prove the causal relationship between the findings found here and to validate their relevance to neuropsychiatric disorders in humans.     

Prenatal thumb sucking is related to postnatal handedness

This study followed-up 75 individuals who were observed sucking their thumb as fetuses and examined their handedness, assessed by a modified version of the Edinburgh Handedness Inventory, at 10-12 years of age. Of 60 right-handed fetuses, all were right-handed postnatally; 10 of 15 left-handed fetuses were left-handed and five right-handed. Male left thumb sucking fetuses were more likely to be right-handed children than females. The study indicates that the prenatal exhibition of lateralised motor behaviour, in this case thumb sucking, is indeed related to postnatal handedness, perhaps more strongly for right 'handed' fetuses than left 'handed' fetuses.     

Slitrk1-deficient mice display elevated anxiety-like behavior and noradrenergic abnormalities

Mutations in SLITRK1 are found in patients with Tourette's syndrome and trichotillomania. SLITRK1 encodes a transmembrane protein containing leucine-rich repeats that is produced predominantly in the nervous system. However, the role of this protein is largely unknown, except that it can modulate neurite outgrowth in vitro. To clarify the role of Slitrk1 in vivo, we developed Slitrk1-knockout mice and analyzed their behavioral and neurochemical phenotypes. Slitrk1-deficient mice exhibited elevated anxiety-like behavior in the elevated plus-maze test as well as increased immobility time in forced swimming and tail suspension tests. Neurochemical analysis revealed that Slitrk1-knockout mice had increased levels of norepinephrine and its metabolite 3-methoxy-4-hydroxyphenylglycol. Administration of clonidine, an alpha2-adrenergic agonist that is frequently used to treat patients with Tourette's syndrome, attenuated the anxiety-like behavior of Slitrk1-deficient mice in the elevated plus-maze test. These results lead us to conclude that noradrenergic mechanisms are involved in the behavioral abnormalities of Slitrk1-deficient mice. Elevated anxiety due to Slitrk1 dysfunction may contribute to the pathogenesis of neuropsychiatric diseases such as Tourette's syndrome and trichotillomania.