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: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=614572
• 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.

早年的环境经历在塑造大脑发育和功能方面的重要性是众所周知的。相比之下，很少有人关注青春期，这是一个大脑不断发育的时期，也是一个在社会行为和许多生理方面与成年期不同的人生时期。我的研究在老鼠身上表明，青春期的社会关系塑造了成年后的社会行为，利用对社会经历(社会不稳定)的操纵，在成年后似乎不会对行为产生持久的影响。在这项拨款中，我们建议调查社会不稳定导致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(如杏仁内侧核)发育的假设。目的2：我们将调查青春期经历了社会不稳定的大鼠表现出的非典型社会行为是否与动机系统和社会学习的社会调节的差异有关。多巴胺能中皮质边缘系统在高动机行为中起关键作用，并在青春期经历显著变化。有很多证据表明，与成年相比，大鼠在青春期的社交互动具有更大的奖励价值，但在社会不稳定之后，这是真的吗？目标3：我们对社会行为的大多数研究只涉及雄性大鼠；这个目标解决了这一差异。我们将调查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，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导致青少年和成年人神经内分泌反应的不同模式。这些神经内分泌差异可能是社会经历对年龄的特定影响的基础。此外，我们有初步证据表明，青春期后青少年与成人之间的神经内分泌系统之间的关系不同；尽管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，我们发现睾酮促进了肾上腺激素的释放。因此，建议通过实验来研究这些年龄差异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春期知识空白的重要步骤，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移植的技能。