ADOLESCENCE: A SENSITIVE PERIOD FOR SHAPING THE ADULT SOCIAL BRAIN

青春期：塑造成人社交大脑的敏感时期

• 批准号: RGPIN-2016-03714
• 负责人: Mccormick, Cheryl
• 金额: $ 4.44万
• 依托单位: Brock University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=691015
• 关键词: ADOLESCENCE; SENSITIVE; PERIOD; SHAPING; ADULT

The importance of environmental experiences in the early years of life in shaping brain development and function is well known. In comparison, there has been little focus on the adolescent period, a period in which there is ongoing brain development, and a time of life that is different from adulthood in terms of social behaviour and many aspects of physiology. My research has shown in rats that social relationships in adolescence shape social behaviour in adulthood, using a manipulation of social experiences (social instability) that seems to have no lasting effect on behaviour when experienced in adulthood. In this grant, we propose to investigate the neural underpinnings of the social instability-induced changes in social behaviour of adolescents. Objective 1: We will test the hypothesis that social experiences in adolescence alter the development of regions of the brain (eg., the medial amygdala). Objective 2: We will investigate whether the atypical social behaviour exhibited by rats that underwent social instability in adolescence involves differences in the social regulation of motivational systems and social learning. The dopaminergic mesocorticolimbic system plays a crucial role in highly motivated behaviours and undergoes significant change in adolescence. There is much evidence that social interactions carry greater reward value in adolescence than in adulthood in rats, but is this true after social instability? Objective 3: Most of our studies of social behaviour have involved male rats only; this objective addresses this disparity. We will investigate the effects of social instability on social behaviour in females, because many sex differences emerge in adolescence and the effects of social instability likely differ for males and females. Objective 4 is based in part on our evidence that the experience of social instability results in a different pattern of neuroendocrine responding in adolescents and adults. These neuroendocrine differences may be a basis for the age-specific effects of social experiences. Further, we have preliminary evidence that relationships between neuroendocrine systems are different for post-pubertal adolescents than for adults; whereas testosterone typically dampens the release of adrenal hormones in response to environmental challenges, in adolescents we found testosterone heightened adrenal hormone release. Thus, experiments are proposed to investigate the mechanisms underlying these age differences the relationships between these hormonal systems. The experiments of my research program are important steps in addressing gaps in our knowledge of the adolescent period of life, which will contribute to the understanding the developmental mechanisms and social experiences that build the social brain. Further, the research program will provide excellent research training and transferrable skills for undergrad and graduate students.**

生命早期的环境经历对于塑造大脑发育和功能的重要性是众所周知的。相比之下，人们很少关注青春期，这是一个大脑持续发育的时期，也是一个在社会行为和生理学许多方面与成年期不同的时期。我对老鼠的研究表明，青春期的社会关系通过操纵社会经历（社会不稳定）来塑造成年后的社会行为，而这种操纵似乎对成年后的行为没有持久影响。在这笔赠款中，我们建议调查社会不稳定引起的青少年社会行为变化的神经基础。目标 1：我们将检验青春期社会经历改变大脑区域（例如内侧杏仁核）发育的假设。目标2：我们将研究青春期经历社会不稳定的大鼠表现出的非典型社会行为是否涉及动机系统和社会学习的社会调节差异。多巴胺能中皮质边缘系统在高度动机行为中发挥着至关重要的作用，并在青春期经历显着变化。有大量证据表明，对于老鼠来说，青春期的社会互动比成年期的奖励价值更大，但在社会不稳定之后，情况是否如此呢？目标 3：我们大多数社会行为研究仅涉及雄性大鼠；这一目标解决了这一差距。我们将研究社会不稳定对女性社会行为的影响，因为许多性别差异出现在青春期，并且社会不稳定对男性和女性的影响可能不同。目标 4 部分基于我们的证据，即社会不稳定的经历会导致青少年和成人不同的神经内分泌反应模式。这些神经内分泌差异可能是社会经历对年龄特定影响的基础。此外，我们有初步证据表明，青春期后青少年的神经内分泌系统之间的关系与成人不同。虽然睾酮通常会抑制肾上腺激素的释放以应对环境挑战，但在青少年中，我们发现睾酮会增加肾上腺激素的释放。因此，建议进行实验来研究这些年龄差异背后的机制以及这些荷尔蒙系统之间的关系。我的研究项目的实验是解决我们对青少年时期生活知识差距的重要步骤，这将有助于理解构建社交大脑的发展机制和社会经验。此外，该研究计划将为本科生和研究生提供出色的研究培训和可转移技能。**