Remodeling in the Prefrontal Cortex of a Brain-related to Higher Executive Functions in Adolescence: Its effects on Behavior
Tin Moe Nwe1, San San Aye2, Khin Than Yee3, Soe Lwin4, Vidya Bhagat5
1Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, UNIMAS.
2Unimas Health Center, UNIMAS.
3Department of Paraclinical Sciences, Faculty of Medicine and Health Sciences, UNIMAS.
4Department of Obstetrics and Gynecology, Faculty of Medicine and Health Sciences, UNIMAS,
5Institute of Hospital Administration, Rajiv Gandhi Medical University, A.J Hospital and Research Center, Mangalore India.
*Corresponding Author E-mail: 55vidya42@gmail.com
ABSTRACT:
Adolescence is a critical stage of the developmental trajectory, where a child’s transition to independent living may result in healthy or unhealthy styles. During this period, it is easier to mend an individual as a healthy adult; at the same time, misguided children may enter into risky behaviors. The aim of the study to get an insight into changing brains of adolescents and their behavioral outcomes. The current review search engine proceeds with reviewing the literature in the past through electronic databases such as PubMed, Medline, and Scopus databases using keywords such as adolescent stage, the brain of teenagers, risk behaviors, reduction in gray matter in the prefrontal cortex. The current study reviewed and analyzed 20 articles. The reviewed articles would increase the awareness and insights regarding brain changes and their behavioral outcomes. This insightful information’s drawn out of the study may help professionals and parents who intervene the adolescent’s problem behaviors.
KEYWORDS: Adolescent stage, Changing Brain of teenagers, Risk Behaviors, Reduction in Gray matter in Prefrontal Cortex.
INTRODUCTION:
Adolescence is a time of restructuring of the brain, which brings the changes in its structure and functions, especially in the prefrontal cortex the new neuronal networking is formed; this part of the brain is connected to higher executive functions involved in planning, decision making, and social behaviors. One of the research in the literature reveals the developmental trajectory of postnatal brain seen with the maximum density of gray matter, which is observed first at the primary sensorimotor cortex, this reviewed study further reveals the prefrontal cortex matures last [1] at around the age of 13 to 20. The adolescent brain is modeled by structural changes through the reconstruction of neuronal networking. [2] In the developmental trajectory of life span the adolescence phase of life comes between late childhood and adulthood. [1]
Adolescence is a period that brings physical and mental maturation in growing children as they grow as adolescents; their emotional maturity achieved at this period forms the adolescents as an independent and responsible adult to fit into their society. The past works of literature have well defined the developmental aspects of adolescence upraised to establish intimate relationships and the development of personal identity, their perspectives of future life, to function as an independent individual; their self-growth leads to gaining self-confidence, self-control, and skill expansion, which helps them to be a part of the social system [3]
The reformation of the brain takes place in adolescence, in which the old neurons are pruned off and replaced by new neurons, especially in the prefrontal cortex, which is proven by structural and functional MRIs exemplified in the reviewed studies of literature. [4]
This reorganization of the structural and functional changes of adolescent brain is an important development needed for the individuation process that prepares an adolescent to play an independent role in society as a responsible adult. Studies have proven on the basis of evidence that the major neural restructuring taking place along with forming new relationships and expanding their socialization with family, friends and others with effective interpersonal relationships. It's important to build positive relationships between parents and their teens to protect them from the negative effects of their socialization and economic activities along with the ongoing developmental changes that take place in the brain. [5]
The limbic system and the reward systems are the subcortical brain areas, which develop earlier with their maturity than that of the prefrontal areas. Thus the subcortical areas are not well executed since the prefrontal areas are under the process of development, this imbalance during adolescence accounts for typical adolescent behavior, which paves the way for risk-taking behaviors. [6]
Adolescence is a critical period of development led by various maturational changes. The neurobiological changes in the prefrontal cortex and other parts of the brain processes, associated with cognitive functions and affected intellectual behavior, social behavior, and emotional behavior. [7]
Neuroscience has projected an insightful understanding of the neurobiological changes; there is a surge in new magnetic resonance imaging [structural and functional MRIs] to cover up information on neurocognitive changes that ensue during the transition from childhood to adolescence. Structural imaging data indicate progressive and regressive changes in the volumes of specific brain regions, although total brain volume is not significantly altered. [8]
An analysis of reviews actualized that the prefrontal cortex matures later than that of other regions of the brain. The development seen in the prefrontal cortex correspondingly increases the abilities in abstract reasoning, shift attention, inhibition instinctual and emotional responses, and processing speed. [9] Adolescents' emotional capacity showed improvement in affectivity with the modulating and discriminating of emotional cues. [10] The functional magnetic imaging studies have revealed the cognitive and affective challenges in frontal cortical neuronal network involve developmental changes in its functional process. [11]
The contributions of neuroscience shed light on adolescent brain development and behavioral changes
The adolescents' neurobiological maturity is understood as complex because the progression in the brain development process is not even all over the brain regions. Consequently, the adolescent's brain is derived from its communication within the system, which leads to disturbances in its functional level and has an effect on adolescent behavior. Children who enter into adolescence are undergoing individuation process to form their personal identity, during this period their socialization extends outside the family. They search for acceptance in the peer group, thus are vulnerable to peer pressure and more sensitive to stress. Their affectivity becomes more unstable, thus express low tolerance to frustration. Their emotional reactivity shows impulsivity, and self-regulatory capacity weakens. Emotion regulation is a substantial development that transversely appears in the adolescence period, which is characteristically led by developing regulatory in the neural circuitry. [11]
Brain changes in adolescents lead to various risk behaviors stated in one of the studies in the literature. This study further reveals risk behavior in adolescents appears more frequently than that of other ages. This reviewed study also comments misbehavior norms and social conventions characteristically are highest between the ages of 17 and 19 years. [12]
Previous studies have debated about the age to achieve criminal responsibility in social situations. Researchers also argued that adolescents are still at a developmental stage, thus ascribing to adolescents’ rights in their decision-making and thoughtful of autonomy. [13]
Moreover, in adolescence, the structural and functional alterations in the prefrontal region advance self-control as they improve the network in the areas related to emotions, such as the limbic system that plays a role in the interaction between cognitive and emotional behaviors. [14] Previous studies describe the areas that control the rewarding process, social information, and emotions sensitive and more easily stimulated in adolescence, especially in the middle adolescence period. [15]
The cognition–emotion boundary reassures the intonation of activations flickered by social and affective stimuli. The deliberate reasoning appears in adolescents by an effective organization amid the cortical and subcortical regions. The studies have also revealed, this procedure goes with bidirectional control, which is deliberated in decision-making with social and emotional evidence. Previous studies have actualized these modifications control the impulsive hunt for sensations and resist peer influence in adolescents. As they move into adulthood, their risk-taking behaviors decrease. [16]
Many parents do not understand their adolescent child is undergoing developmental calamity, which is expressed in their behaviors such as impulsive, irrational, and risk-prone. The adolescent's thinking is affected by brain changes; they do not think about the consequences of their actions. In the adolescence stage of development, teens are not yet gain the adult maturity. Thus adolescent’s way of behaving, solving problems, and making decisions is based on their immaturity at this stage of life. The researches in the past have stated a biological explanation for this difference between adolescents and adults. Studies have demonstrated the chronology of brain development into maturity through childhood, adolescence, and complete into early adulthood. [17]
Researchers have well appreciated an important part of the brain known as the amygdala, which is responsible for immediate reactions of individuals, such as fear and aggressive behavior which is more sensitive in adolescence. In adolescents, the amygdalin reactions are not executed well since the prefrontal area is under development. This part of the brain develops earlier than higher centers of the brain, such as the prefrontal cortex. Basically, the prefrontal cortex of the brain controls thinking, reasoning, and decision-making. This part of the brain helps to think before the acts, which develops much later than the amygdala. This part of the brain gains its maturity well into adulthood. [18]
Other changes in the brain during adolescence include a rapid increase in the connections between the brain cells and making the brain pathways more effective. Nerve cells develop myelin, an insulating layer that helps cells communicate. All these changes are essential for the development of coordinated thought, action, and behavior.
Studies have depicted the Images of the brain in action in adolescents' work differently than adults especially while making decisions or solving problems. Perhaps at this stage of life, due to brain remodeling, different parts of the brain remain out of their network, the matured amygdala in the adolescent brain, yet to connect the executive part of the brain. [19]
Adolescence actions are guided by the emotional and reactive amygdala no control of executive function of prefrontal area thus less thoughtful and logical. Research has shown conditional learning among adolescence and getting exposed to drugs and alcohol during adolescence. Based on brain development, adolescents may exhibit behaviors; such as acting impulsively, misjudge social cues and emotions, get into coincidences of all kinds, and involved in fights. Do not think before they act and consequences of their actions and they are ignorant about their inappropriate behaviors. [20]
With this complexity of the brain, changes don't mean that adolescent people can't make good decisions between right and wrong. It also means that they are responsible for their actions. An awareness of these aspects can help parents, teachers, and rule-makers to appreciate, perceive, anticipate, and fare the behavior of adolescents. [21] The recent scientific evidence shows that frontal brain regions, which are associated with planning, organization, and controlling actions inhibitory, are yet under developing phase until the end of adolescence since these regions are last to mature in the development of the brain. [22]
The analysis of previous brain imaging studies supports a view that remodeling of the frontal and prefrontal cortex embraces progressively regulatory roles during adolescence. These neurobiological changes are meant to contribute to the range in cognitive and affective behavior of adolescence. [23]
Previous reviews reveal that regions that are reward-sensitive interconnected to emotions area are highly active and accelerated emotional reactivity. [24,25] Reviews in the past publicized, that the enhanced activity to a sensitivity with directed focus advances short while in long run the negative may have to confront consequences. As conceptualized, the development and maturation seen with a wider gap between rational and emotional areas of the brain source for adolescent impulsive behavior indulging them into risky behaviors. One of the literature studies reveals temporal space concerning the maturation of rational and emotional systems, and their brittle communication leads to greater susceptibility to risky behavior. [26]
Analyzed reviews observe in different articles dual maturational imbalance in the adolescent brain. The evidence regarding structural and functional brain development throughout adolescence may contribute to sensation seeking. [27] Smith et al., 2018, in their model has stated that the difference in the development of sensation-seeking behaviors and self-control, which partializes the behaviors that seek reward, newness, and risk. [28]
The current study analyses the literature information on neuroscientific evidence with a particular focus on culpability and rehabilitation of adolescents. Insight and developed concepts are meaningful in guiding and rehabilitating problems faced by teens. [29] The analysis of previous studies have led to the realization that unstable affectivity in adolescence paves up to low tolerance, frustration, and emotional reactivity; adolescents' self-regulatory part of behavior is also affected in various levels until they reach the maturity of adulthood. Resultantly the risky behaviors frequently observed during adolescence, [30]
CONCLUSION:
The brain regions that cause attention, reward evaluation, affective discrimination, response inhibition, and goal-directed behavior are impacted by the reconstruction of the nueronal networking during adolescence stage. This structural and functional reorganization takes place in the adolescent brain. The current study conceptualizes with insightful information that are tiled on analysed results of previous literature concerning the developmental stage between late childhood and early adulthood. During this stage the remodeling of the adolescent brain, which promotes the progression in the regulatory role of frontal and prefrontal cortex. These neurobiological changes are the contributing aspect to the range in cognitive and affective behaviors. The awareness among professionals regarding adolescents' developmental trajectory and neuroscientific indications of adolescent’s brain and these changes in adolescent brain affecting behaviors would help them to help their teens. The implications of current neuroscientific evidence would be useful to parents and professionals who intervene with adolescent problems.
CONFLICT OF INTEREST:
Authors declare no conflict of interest.
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Received on 30.06.2021 Modified on 09.07.2021
Accepted on 16.07.2021 ©AandV Publications All right reserved
Res. J. Pharmacology and Pharmacodynamics. 2021; 13(3):99-102.
DOI: 10.52711/2321-5836.2021.00021