Arakawa Hiroyuki
Department of Psychology, Graduate School of Letters, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan.
Physiol Behav. 2005 Mar 16;84(3):429-36. doi: 10.1016/j.physbeh.2005.01.008.
Cage stocking density can be manipulated by changing in cage size and group size in the cage. The effects of these two factors were investigated in three developmental stages in male rats: juvenile, post-pubertal, and adult. An open-field test was conducted to measure exploratory behavior which was influenced by levels of activity, anxiety, and exploration. When the cage size was decreased, juvenile rats displayed decreased locomotion and lower propensity for exploration, whereas such changes were not evident in post-pubertal rats. When the group size was increased, adult rats exhibited higher locomotion. However, these factors did not affect risk assessment behavior of rats in these developmental stages. Thus, it appears that the effect of stocking density differs depending on the developmental stage of the animal: Juvenile rats increased anxiety following limiting space, whereas adult rats increased activity following increase in social tension.
可通过改变笼子大小和笼内动物数量来控制笼养密度。在雄性大鼠的三个发育阶段（幼年、青春期后和成年期）研究了这两个因素的影响。进行旷场试验以测量受活动水平、焦虑和探索影响的探索行为。当笼子大小减小时，幼年大鼠的运动减少且探索倾向降低，而青春期后大鼠中这种变化不明显。当笼内动物数量增加时，成年大鼠表现出更高的运动性。然而，这些因素并未影响这些发育阶段大鼠的风险评估行为。因此，似乎饲养密度的影响因动物的发育阶段而异：空间受限后幼年大鼠焦虑增加，而社会紧张加剧后成年大鼠活动增加。
