During the youth, rats spend a long time in play fighting (PF), and asymmetries are observed in terms of the frequency of adoption of the supine posture. This study investigated the effects of asymmetry in adopting supine posture during PF on the time spent in locomotor activity-related contextual behaviors during youth and adulthood. Male Wistar rats were divided into three groups according to the number of times of their adoption of a defensive supine (S) posture: low (LS, n = 10), intermediary (IS, n = 10) and high (HS, n = 10) Rats aged 21-62 days were placed in voluntary physical active cages (VPAC) with running wheels. The time spent in social play (SP), play fighting (PF), voluntary physical activity (VPA), spontaneous physical activity (SPA) and resting (Rest) were recorded daily. During adulthood (63-92 days of age), rats were placed individually in the VPAC, with daily quantification of VPA. The average time spent in PF was not different among the groups, but was age-dependent. LS and IS rats spent more time in VPA than the HS rats, between days 49-62 (intragroup analyses) and 72-78 (individual analyses) days of age. However, LS and IS animals spent less time in SPA than HS rats from 42-48 days of age. In conclusion, the expressions of VPA and SPA are influenced by the asymmetries in adoption of the supine posture of members within a social group, remaining even after the separation of the social groups.

中文翻译：

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采取防御姿势的频率是否会影响成年大鼠主动行为的表达？

在青年时期，老鼠花很长时间进行打斗（PF），并且在采用仰卧姿势的频率方面观察到不对称。本研究调查了 PF 期间采用仰卧姿势的不对称性对青年和成年期间在与运动活动相关的情境行为中花费的时间的影响。雄性Wistar大鼠根据采取防御性仰卧（S）姿势的次数分为三组：低（LS，n = 10），中间（IS，n = 10）和高（HS，n = 10) 将 21-62 天大的大鼠放置在带有跑轮的自愿身体活动笼 (VPAC) 中。每天记录在社交游戏 (SP)、游戏打架 (PF)、自愿体力活动 (VPA)、自发体力活动 (SPA) 和休息 (Rest) 上花费的时间。在成年期（63-92 天大），将大鼠单独放置在 VPAC 中，每日定量 VPA。在 PF 中花费的平均时间在各组之间没有差异，但与年龄有关。LS 和 IS 大鼠比 HS 大鼠在 VPA 中花费的时间更多，在 49-62 天（组内分析）和 72-78（个体分析）日龄之间。然而，LS 和 IS 动物在 SPA 中的时间少于 42-48 天龄的 HS 大鼠。总之，VPA和SPA的表达受到社会群体内成员采用仰卧姿势的不对称性的影响，即使在社会群体分离后仍然存在。49-62 天（组内分析）和 72-78 天（个体分析）之间的年龄。然而，LS 和 IS 动物在 SPA 中的时间少于 42-48 天龄的 HS 大鼠。总之，VPA和SPA的表达受到社会群体内成员采用仰卧姿势的不对称性的影响，即使在社会群体分离后仍然存在。49-62 天（组内分析）和 72-78 天（个体分析）之间的年龄。然而，LS 和 IS 动物在 SPA 中的时间少于 42-48 天龄的 HS 大鼠。总之，VPA和SPA的表达受到社会群体内成员采用仰卧姿势的不对称性的影响，即使在社会群体分离后仍然存在。