Kikusui Takefumi, Takeuchi Yukari, Mori Yuji
Laboratory of Veterinary Ethology, University of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo 113-8657, Japan.
Physiol Behav. 2004 Mar;81(1):37-42. doi: 10.1016/j.physbeh.2003.12.016.
Early environmental stimuli have been shown to affect many aspects of physiological and behavioral development in humans and other mammals. In this study, we investigated the effects of early weaning on behavioral traits in adulthood. Male and female Balb/c mice were divided into two groups, one weaned from the dam at 14 days of age (early-weaned group) and the other weaned at 21 days of age (normally weaned group), as a control. At 8 and 22 weeks of age, animals of both groups were subjected to the plus maze test to assess their anxiety levels. The early-weaned mice showed lower frequency of entry into the open arms of the maze. Although a subsequent isolation-induced aggression test revealed no clear differences between the two groups, when males from each of the two weaning groups were regrouped after 1 month of isolation, the early-weaned animals showed a great number of wounds on their tails and hindquarters. These results suggest that the deprivation of mother-pup interaction from 14 through 21 postnatal days augments anxiety and aggressiveness.
早期环境刺激已被证明会影响人类和其他哺乳动物生理及行为发育的许多方面。在本研究中，我们调查了早期断奶对成年后行为特征的影响。将雄性和雌性Balb/c小鼠分为两组，一组在14日龄时断奶（早期断奶组），另一组在21日龄时断奶（正常断奶组）作为对照。在8周龄和22周龄时，对两组动物进行十字迷宫试验以评估其焦虑水平。早期断奶的小鼠进入迷宫开放臂的频率较低。尽管随后的隔离诱导攻击试验显示两组之间没有明显差异，但当将两个断奶组的雄性小鼠在隔离1个月后重新分组时，早期断奶的动物尾巴和后躯出现大量伤口。这些结果表明，出生后14至21天剥夺母婴互动会增加焦虑和攻击性。
