The adolescent brain: Changes and challenges of development

Abstract

Adolescence is a period between childhood and adulthood, characterized by specific physical and psychological development. It is a transitional developmental period, rather than a single snapshot in time. Traditional neurobiological and cognitive explanations of adolescent development of behavior have failed to account for the changes in behavior observed during adolescence. Magnetic resonance imaging studies have discovered that myelinogenesis continues from childhood to adulthood in the brain's region-specific neurocircuitry, which remains structurally and functionally vulnerable to impulsive habits. The maturation of the adolescent brain is influenced by heredity, environment, and sex, and they play a crucial role in myelination. Furthermore, one of the measures extracted out of MRI studies is also the thickness of cerebral cortex, a part that harbors synapses. It is the complexity of these synapses that allows humans to generate and understand complex thoughts and feelings in the real world, including the ability to solve analogies. And it is the complexity of those connections, remaining under construction during adolescence, that may be responsible for immature and impulsive behavior and neurobehavioral excitement during the adolescent life. 9 SAŽETAK Adolescencija je period fizičkog i psihološkog razvoja, koji se odvija između detinjstva i perioda odraslog života. To je više prelazni razvojni period nego što je izolovan trenutak u vremenu. Tradicionalna neurobiološka i kognitivna objašnjenja razvoja adolescenta nisu uspela da obrazlože promene u ponašanju koje se primećuju tokom adolescencije. Naučne studije su otkrile da se mijelogeneza nastavlja u specifičnim neuronskim mrežama mozga od detinjstva do zrelosti. Sazrevanje adolescentnog mozga je pod uticajem nasleđa, okruženja i pola, koji igraju presudnu ulogu u mijelinizaciji. Složenost razvoja sinapsi omogućava ljudima stvaranje i razumevanje kompleksnih misli i oseća-nja, uključujući i sposobnost rešavanja analogija u realnom svetu. I sama kompleksnost ovih veza, koje nastavljaju razvoj tokom adolescencije, može da bude odgovorna kako za nezrelo i impulsivno ponašanje, tako i za neurobihejvioralno uzbuđenje tokom adolescentnog života

Adolescent maturation of the prefrontal cortex: Role of stress and sex in shaping adult risk for compromise

“…Myelination is important to the insulation and transmission of charge down the axon thus facilitating signal propagation within the brain . The comparatively lower myelination in the juvenile phase generates a reduced speed of neurotransmission in cortical areas until the myelin maturation process is completed during the transition to adulthood . Combined, synapse refinement and complete myelination establish mature, functioning neurons.…”

“…Although sex differences in the PFC have been showed in rodent and human studies, the critical nature of this region is apparent in both sexes . The PFC is particularly sensitive to adverse experiences during development and is poised for influence of sex‐specific hormonal changes during puberty . The medial PFC (mPFC) is known for its role in decision making and memory, with high functional correlation within this region in both rodents and primates .…”

“…49 The comparatively lower myelination in the juvenile phase generates a reduced speed of neurotransmission in cortical areas until the myelin maturation process is completed during the transition to adulthood. 32,33,48,[50][51][52] Combined, synapse refinement and complete myelination establish mature, functioning neurons. At the same time, dynamic cytoskeletal proteins create the scaffold that supports the shape and function of the cell during these changes.…”

“…Here, we focus on possible structural maturation of the brain that may give rise to sex differences and later life susceptibility to neural disorders either independently or in concert with these factors . Collectively, enhanced neural pruning, the completion of myelination and cytoskeletal alterations mark the completion of adolescence and represent the ontogeny of the adult brain . Therefore, these processes, and disruptions therein, are positioned to be at risk during the adolescent period.…”

“…23,30 Collectively, enhanced neural pruning, the completion of myelination and cytoskeletal alterations mark the completion of adolescence and represent the ontogeny of the adult brain. [30][31][32][33][34] Therefore, these processes, and disruptions therein, are positioned to be at risk during the adolescent period.…”