Neural mechanisms of social status during adolescence

在包括人类在内的动物中，赢得竞争性遭遇会增加未来比赛中获胜的机会，而失败会增加未来再次失败的机会。这些影响的发生是因为赢和输的经历对大脑有不同的影响。这些发现没有解释的是，个人如何从失败过渡到成功。在青少年时期尤其如此，因为此时的个人竞争经验较少，更有可能失败。一种特殊类型的行为策略，社会警惕，可能是促进这种转变的关键机制。社会警惕包括对潜在威胁个体的回避和观察。在这个项目中，研究小组将测试青春期睾丸激素分泌的增加是否有助于男性从社会警惕过渡到更自信的攻击行为。在成年人中，获胜后睾丸激素的短期增加在促进赢家效应中起着关键作用。研究人员预测，青春期的睾丸激素分泌会使促进社会警觉的神经回路脱敏。为了解决这个问题，该项目将确定青春期睾丸激素是否会改变神经回路中神经元的活动，这些神经回路控制社会警惕以及在攻击性遭遇中使用的防御性和攻击性发声。加州大学戴维斯分校是一所西班牙裔服务机构，在支持包容性STEM文化以扩大影响和增加发现方面有着良好的记录。该研究的支持将为STEM领域的历史弱势群体提供培训机会，并通过开放日活动增加社区参与。该项目整合了行为，神经内分泌和生理层面的社会行为分析。以前的研究表明，催产素作用于终纹床核（BNST）增加了社会警觉行为，社会压力增加了催产素神经元的活性。一个关键的假设是，青春期睾丸激素的激增重新编程了BNST中的催产素神经元，使其对社会压力不那么敏感。社会警觉依赖于催产素，在青少年男性中比成年人更普遍。这项研究将首先测试青春期睾丸激素的增加是否会降低男性和女性的压力引起的警惕性。应激对催产素神经元长时程增强（LTP）的影响将被检查，以及应激对LTP的影响是否受青春期睾酮暴露的调节。在大鼠海马体和斑胸草雀的鸣唱控制系统中，睾酮在青春期起作用以减少LTP。最后，青春期睾酮对领土形成的影响将通过观察攻击性行为和领土形成过程中使用的特征明确的断言和被动发声来研究。这些研究的结果将为了解促进脊椎动物物种之间发生的社会转变的神经回路提供重要的见解。该项目还将产生新的工具，包括青少年加州小鼠大脑的大脑图谱，将托管在brainmaps.org上。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

In animals including humans, winning a competitive encounter increases the chances of winning in future contests while losing increases the chance losing again in the future. These effects occur because the experience of winning and losing have different effects on the brain. What these discoveries do not explain, is how individuals can transition from losing to winning. This is especially true during adolescence, when individuals have less competitive experience and are more likely to lose. A specific type of behavioral strategy, social vigilance, may be a key mechanism for facilitating this transition. Social vigilance involves a combination of avoidance and observation of potentially threatening individuals. In this project, the research team will test whether increased testosterone secretion during adolescence facilitates a transition from social vigilance to more assertive aggressive behaviors in males. In adults, short term increases in testosterone after winning play a key role in facilitating winner effects. The researchers predict that the testosterone secretion during adolescence desensitizes neural circuits that promote social vigilance. To address this question this project will determine whether testosterone acts during puberty to alter the activity of neurons within neural circuits that control social vigilance as well as defensive and offensive vocalizations used in aggressive encounters. The University of California at Davis is a Hispanic Serving Institution with a strong track record of supporting an inclusive STEM culture to broaden impact and increase discovery. Support of this research will provide training opportunities for historically disadvantaged groups in STEM and increase community engagement via open house events.This project integrates behavioral, neuroendocrine, and physiological levels of analysis of social behavior. Previous work shows that oxytocin acting in the bed nucleus of the stria terminalis (BNST) increases social vigilance behavior, and that social stress increases the activity of oxytocin neurons. A key hypothesis is that the pubertal surge of testosterone reprograms oxytocin neurons in the BNST to be less sensitive to social stress. Social vigilance is oxytocin dependent, and more prevalent in juvenile males than adults. This research will first test whether increased testosterone during puberty reduces stress-induced vigilance in males and females. The effects of stress on long term potentiation (LTP) of oxytocin neurons will be examined and whether the effects of stress on LTP are modulated by pubertal testosterone exposure. In the rat hippocampus and the zebra finch song control system testosterone acts during puberty to reduce LTP. Finally, the effects of pubertal testosterone on territory formation will be studied by observing aggressive behaviors and the use of well characterized assertive and passive vocalizations during territory formation. Results from these studies will provide important insights into the neural circuits that facilitate social transitions that occurs across vertebrate species. This project will also generate new tools, including a brain atlas of the adolescent California mouse brain which will be hosted on brainmaps.org.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.