The study on the factors determining the effects of isolation rearing on social behavior in male laboratory mice

将ICR雄性小鼠隔离饲养或与7周龄的雌性小鼠一起饲养。两周后进行抗扭试验。从4周龄开始，ICR雄性在下列条件下饲养：（1）单独饲养，（2）用透明塑料板隔开，（3）用小或大网眼铁丝网隔开，（5）成对饲养。五周后，进行社会接触测试。与条件（5）相比，条件（1）和（2）中攻击性的增加比条件（3）和（4）中更多，而条件（1）-（4）中胆怯反应的增加。实验结果表明，ICR雄性从4周龄开始单独饲养，从7周龄开始与雌性配对饲养，从3周龄开始与雌性成组饲养。在九周大时进行了接触测试。4 ~ 7天后取出脑，测定单胺及其代谢产物的含量。隔离减少单胺和增强中脑边缘多巴胺能活性。肾上腺素和5-羟色胺在主要表现出攻击性或胆怯反应的动物中大量减少。社会交往过程中的隔离和神经活动。ICR雄性动物从4周龄起被隔离或分组饲养。六到七周后，他们遇到了另一只被关在一个小铁丝网笼子里的雄性，然后对大脑进行灌注和固定，检查c-Fos表达作为神经活动的量度。结果提示，隔离可能增强了主要嗅觉通路的敏感性和杏仁核及其投射区的兴奋性。

Isolation and cohabitation with a female in male residents.ICR male mice were reared in isolation or with a female from seven weeks old. Two weeks later ain truder test was performed. The effects of isolation differed from those of cohabitation with a female.Social experiences and adult social behavior.ICR males were reared from four week old in the following conditions :(1)singly housed, or separated with the partition made of (2)transparent plastic board, (3)small- or (4)large-meshed wire net, or (5)paired. Five week later a social encounter test was performed. Compared with condition (5),aggression increased more in conditions (1)and (2)than in conditions (3)and (4),whereas timid responses increased in conditions (1)-(4). The results suggested that different experiences were involved in aggression and timid responses.Isolation and monoaminergic systems.ICR males were (1)singly housed from four weeks old, (2)paired with a female from seven weeks old, or (3)reared in a group from three weeks old. An encounter test was performed at nine weeks old. Four to seven days later the brains were removed and the contents of monoamines and their metabolites were measured. Isolation reduced monoamines and enhanced the mesolimbic dopaminergic activity. Adrenalin and serotonin reduced largely in the animals dominantly showing aggression or timid responses.Isolation and neural activities during social interaction.ICR males were reared in isolation or in a group from four weeks old. Six to seven weeks later they encountered with another male confined in a small wire-mesh cage, and then the brains were perfused and fixed, c-Fos expression was examined as a measure of neural activity. The result suggested that sensitization especially in the main olfactory pathway and excitability in the amygdala and its projecting regions might be enhanced by isolation.