Adolescence is a period of dramatic neural reorganization creating a period of vulnerability and the possibility for the development of psychopathology. The maturation of various neural circuits during adolescence depends, to a large degree, on one's experiences both physical and psychosocial. This occurs through a process of plasticity which is the structural and functional adaptation of the nervous system in response to environmental demands, physiological changes and experiences. During adolescence, this adaptation proceeds upon a backdrop of structural and functional alterations imparted by genetic and epigenetic factors and experiences both prior to birth and during the postnatal period. Plasticity entails an altering of connections between neurons through long-term potentiation (LTP) (which alters synaptic efficiency), synaptogenesis, axonal sprouting, dendritic remodeling, neurogenesis and recruitment (Skaper et al., 2017). Although most empirical evidence for plasticity derives from studies of the sensory systems, recent studies have suggested that during adolescence, social, emotional, and cognitive experiences alter the structure and function of the networks subserving these domains of behavior. Each of these neural networks exhibits heightened vulnerability to experience-dependent plasticity during the sensitive periods which occur in different circuits and different brain regions at specific periods of development. This report will summarize some examples of adaptation which occur during adolescence and some evidence that the adolescent brain responds differently to stimuli compared to adults and children. This symposium, "Experience during adolescence shapes brain development: from synapses and networks to normal and pathological behavior" occurred during the Developmental Neurotoxicology Society/Teratology Society Annual Meeting in Clearwater Florida, June 2018. The sections will describe the maturation of the brain during adolescence as studied using imaging technologies, illustrate how plasticity shapes the structure of the brain using examples of pathological conditions such as Tourette's' syndrome and attention deficit hyperactivity disorder, and a review of the key molecular systems involved in this plasticity and how some commonly abused substances alter brain development. The role of stimulants used in the treatment of attention deficit hyperactivity disorder (ADHD) in the plasticity of the reward circuit is then described. Lastly, clinical data promoting an understanding of peer-influences on risky behavior in adolescents provides evidence for the complexity of the roles that peers play in decision making, a phenomenon different from that in the adult. Imaging studies have revealed that activation of the social network by the presence of peers at times of decision making is unique in the adolescent. Since normal brain development relies on experiences which alter the functional and structural connections between cells within circuits and networks to ultimately alter behavior, readers can be made aware of the myriad of ways normal developmental processes can be hijacked. The vulnerability of developing adolescent brain places the adolescent at risk for the development of a life time of abnormal behaviors and mental disorders.

中文翻译：

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青春期的经历影响着大脑的发育：从突触和网络到正常和病理行为。

青春期是剧烈的神经重组的时期，会造成脆弱的时期以及心理病理学发展的可能性。青春期各种神经回路的成熟在很大程度上取决于一个人的身体和心理社会经历。这是通过可塑性过程发生的，可塑性过程是神经系统响应环境需求，生理变化和经历而适应结构和功能的过程。在青春期期间，这种适应在遗传和表观遗传因素赋予的结构和功能改变以及出生前和出生后经历的背景下进行。可塑性需要通过长期增强（LTP）（改变突触效率），突触形成，轴突发芽，树突重塑，神经发生和募集（Skaper等人，2017）。尽管可塑性的大多数经验证据来自于感觉系统的研究，但最近的研究表明，在青春期，社交，情感和认知经验会改变支持这些行为域的网络的结构和功能。这些神经网络中的每一个在敏感时期对依赖于经验的可塑性表现出更高的脆弱性，这些敏感时期发生在特定发育时期的不同电路和不同大脑区域。该报告将总结一些在青春期发生的适应性例子，以及一些证据表明，与成人和儿童相比，青春期大脑对刺激的反应不同。本次研讨会 促进理解同龄人对青少年危险行为的影响的临床数据为同龄人在决策中所扮演角色的复杂性提供了证据，这种现象不同于成年人。影像学研究表明，在决策时由同伴的参与激活社交网络在青少年中是独特的。由于正常的大脑发育依赖于改变电路和网络中细胞之间的功能和结构联系以最终改变行为的经验，因此可以使读者意识到劫持正常发育过程的多种方式。发育中的青少年大脑的脆弱性使青少年处于发展异常行为和精神障碍的一生中的危险中。