年龄及性别对小鼠新物体再认能力和旷场行为的影响

Age and sex for the ability of novel-object recognition and the behaviors in open field in mice

目的:研究年龄、性别对小鼠新物体再认(novel-objectrecognition)能力和旷场活动的影响,了解两类行为间的关系。方法:实验于2004-05在安徽省老年病研究所行为学实验室完成。入组的47只昆明小鼠被分成两组:青年组(七八月龄,12雄、11雌)和老年组(十七八月龄,12雄、12雌)。采用新物体再认任务检测小鼠的非空间短期记忆能力,采用旷场任务检测小鼠的探索活性(locomotor)行为,并用主因子分析判断任务间的关系。结果:在新物体再认记忆任务中,老年雌鼠的新物体优先指数为(55.6±4.9)%,显著低于年轻雌鼠(66.6±3.7)%。在旷场任务中,老年雌鼠的探索运动活性减低,并且雌雄老年鼠在旷场周边所花的时间犤(294.4±2.0),(289.3±4.3)s犦比各自对应的青年小鼠犤(278.2±4.9),(267.2±6.3)s犦均多。新物体再认成绩与旷场任务中的周边时间呈正相关,而与跨格数负相关。结论:雌性老年昆明小鼠有新物体再认(短期记忆)能力损害,且受旷场行为影响。

AIM:To investigate the effect of age and sex on novel object recognition ability and open field behaviors of mice,and the relationship between two kinds of behaviors. METHODS:The experiment was completed in the Behavior Laboratory,Anhui Institute of Senile Diseases.Forty seven Kunming mice were grouped according to the age:23 younger mice aged 7-8 months,and 24 older mice at the age of 17-18 months.Two tasks including open field and novel object recognition were used to determine non spatial short term memory and locomotor of mice.A principal component analysis was employed to reveal whether these tasks are independent or correlated with each other. RESULTS:The female older Kunming mice exhibited lower locomotor activity in the open field task relative to younger female mice and older male mice.Moreover,older male and female mice spent a longer time in the peripheral squares of the open field[(289.3 ±4.3) s,(294.4 ±2.0) s]than younger male and female ones[(267.2 ±6.3) s,(278.2 ±4.9) s].In the novel object recognition task, a non spatial cognitive task, older female mice but not older male mice had more obvious impairment of short term memory compared with the younger female mice[the preferential index for novel object:(55.6 ±4.9)%vs (66.6 ±3.7)%].The non spatial cognitive performance in the novel object recognition task was positively related to the number of squares crossed and negatively related to the peripheral time in the open field task. CONCLUSION:Disturbance of non spatial memory exists in older female Kunming mice,which is affected by the open field behavior.