Department of Behavioural Biology, University of Münster, Münster, Germany; Münster Graduate School of Evolution, University of Münster, Münster, Germany.
Horm Behav. 2024 Jun;162:105539. doi: 10.1016/j.yhbeh.2024.105539. Epub 2024 Apr 11.
Individualized social niches arise in social groups, resulting in divergent social behavior profiles among group members. During sensitive life phases, the individualized social niche can profoundly impact the development of social behavior and associated phenotypes such as hormone (e.g. cortisol) concentrations. Focusing on adolescence, we investigated the relationship between the individualized social niche, social behavior, and cortisol concentrations (baseline and responsiveness) in female guinea pigs. Females were pair-housed in early adolescence (initial social pair formation), and a social niche transition was induced after six weeks by replacing the partner with either a larger or smaller female. Regarding social behavior, dominance status was associated with aggression in both the initial social pairs and after the social niche transition, and the results suggest that aggression was rapidly and completely reshaped after the social niche transition. Meanwhile, submissive behavior was rapidly reshaped after the social niche transition, but this was incomplete. The dominance status attained in the initial social pair affected the extent of submissive behavior after the social niche transition, and this effect was still detected three weeks after the social niche transition. Regarding cortisol concentrations, higher baseline cortisol concentrations were measured in dominant females in the initial social pairs. After the social niche transition, cortisol responsiveness significantly increased for the females paired with a larger, older female relative to those paired with a smaller, younger female. These findings demonstrate that the social niche during adolescence plays a significant role in shaping behavior and hormone concentrations in females.
个体社会生态位出现在社会群体中，导致群体成员之间存在不同的社会行为特征。在敏感的生命阶段，个体社会生态位会深刻影响社会行为以及相关表型的发展，例如激素（如皮质醇）浓度。本研究以青春期雌性豚鼠为研究对象，关注个体社会生态位、社会行为和皮质醇浓度（基础值和反应性）之间的关系。雌性豚鼠在青春期早期进行成对饲养（初始社会配对形成），六周后通过更换体型较大或较小的雌性个体来诱导社会生态位转变。在社会行为方面，无论是在初始社会对还是在社会生态位转变后，支配地位都与攻击行为有关，结果表明攻击行为在社会生态位转变后迅速而完全地重塑。与此同时，顺从行为在社会生态位转变后迅速重塑，但并不完全。在初始社会对中获得的支配地位会影响社会生态位转变后顺从行为的程度，这种影响在社会生态位转变后三周仍然存在。就皮质醇浓度而言，在初始社会对中，处于支配地位的雌性豚鼠的基础皮质醇浓度较高。在社会生态位转变后，与体型较小、年龄较小的雌性个体配对的雌性豚鼠，其皮质醇反应性显著增加，而与体型较大、年龄较大的雌性个体配对的雌性豚鼠则显著增加。这些发现表明，青春期的社会生态位在塑造女性的行为和激素浓度方面发挥着重要作用。
