Introduction
An adolescent’s neurological development is complex and dynamic,- yet it is a vital and necessary task that influences cognitive, emotional, and behavioral aspects. Although genetics do contribute to a child’s brain development, a child’s environment plays a key aspect to their neurodevelopment. Prenatal and postnatal factors are the foundation for children’s brain development while also implicating long-term outcomes.
During the first few years of a child’s life, children go through a transformative period. During this phase, one’s brain goes through extensive growth, organization, and maturing- resulting in the growth of critical thinking skills and personalities that affect one’s life. More than a million new neural connections are formed in each section during this cycle. However, after this period of highly sensitive brain development, these connections are reduced by a series of processes of the elimination of extra synapses (brain structures that allow for neurons to transmit an electrical or chemical signal to another neuron). This is called synaptic pruning. According to Cafasso (2018), synaptic pruning is the brain’s way of removing connections in the brain that are no longer needed- maintaining how one processes information more efficiently as humans mature and gain more complexity in terms of learning new skills or information. This allows children to develop sensory pathways, for example, taste and hearing, and then basic language skills and more complex cognitive skills.
“The most important thing that parents need to understand is that the brain of their child will become exactly what the child was exposed to. … That is the beauty of the human brain. It is the mirror to the child’s developmental experience.” -Bruce D Perry M.D., Ph.D.
Children nurtured in a safe environment develop and learn the best rather than being in a neglectful environment with extreme or chronic stress (Centers for Disease Control and Prevention, 2019). Parents, guardians, or other caregivers can support and provide many opportunities for their children by speaking to, initiating play, and providing care. By offering the following responsive care, this exposes children to using and processing complex information- strengthening vital cognitive functions such as critical thinking, language and communication, memory development, and auditory perception development (Nees, 2023).
Environmental Factors
Prenatal: Maternal Influences
This period is a sensitive period of development- where exposure to malnutrition, infection, or stress, can have long-term or permanent impacts on the health of a child. This is called developmental programming. Here is how these external influences can have permanent impacts on a child:
1) Nutrition
During pregnancy, nutrition is more important than ever- helping both the mother and child maintain a proper and healthy weight. In particular, folic acids, iron, calcium, and Vitamin D should be consumed more often. Folic acids are a B vitamin that can help prevent most neural tube defects, which are usually diagnosed before the infant is born. Neural tube defects are usually permanent due to the nerve damage that occurs, however, taking folic acid supplements during pregnancy can sometimes prevent further neurological damage. Due to the increase of blood during pregnancy, mothers need more iron for themselves and for their babies; iron also affects a child’s growth and neurological development. Calcium can reduce the risk of preeclampsia (a medical condition that causes a sudden increase in blood pressure) while also aiding in the development of a child’s bones and teeth. On the other hand, Vitamin D helps the calcium build the baby’s bones and teeth.
2) Infection
Viral infections during pregnancy by pathogens such as Zika virus, Cytomegalovirus, Rubella, and Herpes Simplex virus can lead to prenatal and post-natal neurodevelopmental disorders- having harsh congenital health conditions for the fetus. Intrauterine inflammation can have an increased risk of neurodevelopmental disorders like schizophrenia, autism spectrum disorder, and epilepsy. According to Lee et al. (2020), gestational viral infections during pregnancy can lead to schizophrenia and related psychoses, also having adverse consequences on children’s neurological development.
3) Stress
The hypothalamic-pituitary-adrenal (HPA) axis, a set of direct connections among the hypothalamus, the adrenal glands, and the pituitary gland, is activated when one undergoes through a high stress situation- it prepares how one reacts to stress and acts as a neutralizing mechanism by preparing the human body after a stressful situation. This usually leads to the hypothalamus stimulating the pituitary gland to give off hormones that cause the adrenal glands to release cortisol (which is used to prepare the human body for “fight or flight” mode.” According to Maniam, Antoniadis, and Morris (2014), research conducted on epidemiology, clinical, and experimentation reveals that exposure to early-life stress causes long-term over reactivity to stressful situations. This leads to increased levels of circulating glucocorticoids, a group of corticosteroids that help one’s body respond to stress and regulate how the body uses fats and sugars, and amplified anxiety and depressed behavior.
Postnatal: Childhood Experiences
A child’s exposure to a safe, postnatal area becomes a key factor. Throughout this period, the human brain experiences a drastic increase in brain volume and activity, cortical grey matter structures, and cortical white matter structures- these processes establish the neural framework in one’s brain that inhibits the ability to perform cognitive and motion functions. Any disruption or lack of these mechanisms can be linked to the emergence of childhood neurodevelopmental and psychiatric disorders.
Neurodevelopmental Outcomes: Cognitive, Emotional, and Behavioral Development
Environment can impact on various aspects of a child’s development- affecting cognitive abilities, emotional regulation, and behavioral plays. Adolescents who grow up in a nurturing responsive, stimulating environment tend to exhibit better cognitive and emotional development and skills while those who face high stress and neglect experience difficulties involving these areas. Emotional well-being and social competence build a solid foundation for these cognitive abilities- the emotional, physical, social, and cognitive-linguistic skills that emerge after synaptic pruning are crucial for the child’s future as they serve as prerequisites for success in neurologic development.
Epigenetic Modifications: How Genetics and Environment Affect the Human Brain
The maturation of the human brain is led by genetic programs during the embryonic and fetal stages. A neural map of connections and the basis of learning, which is called connectomes, continues to form, develop, and restructure throughout life. Learning new skills and information requires cognitive operations such as memory development, attention span, intelligence, cognitive control, and executive functions. In other words, neurological activity is influenced by its development and its formation of connectomes. All mental functions, including learning, are shaped by the human brain activity. The continuous human pursuit of knowledge is possible due to the formation of several connectomes that support mental activity and function. Gene activity and epigenetic modifications, how the environment plays a factor in modifying gene expression but not gene structure, regulate gene expression in response to environmental conditions. This results in the impact of brain formation, function, and neural plasticity, which is the brain’s way of changing and adapting in response to experience, stimulation, or injury. This neurological development of the brain is influenced by both genes and the environment, as well as the interaction between the two. Epigenetic modifications can affect neural connectivity and gene activity in response to certain environmental factors- including familial, social, and educational areas.
The neurological study of mechanisms and phenomena that alter gene expressions inherited during cell replication is known as epigenetics. Epigenetic changes begin during the prenatal period. All cells have the same genetic material; however, some appear and act differently. As one grows, epigenetics helps determine which function a cell has- whether it’ll become a heart cell, nerve cell, or skin cell. The epigenome, the pattern of epigenetic modifications in a cell at a given time, is not identical to all cells, however- unlike the genome. Environmental factors are the foundation that shape the epigenome and cause it to change throughout a human’s lifespan.
Epigenetic changes are what regulate the expression of genes that are involved in neural plasticity and neural physiology. These changes can be applicable to cognitive ability and learning new skills- especially during childhood when children are more adaptable to their environment, and develop cognitive flexibility towards new changes. Epigenetic signatures are adaptive and differentiate based on experiences and environmental conditions. Certain gene’s epigenetic signatures, for example, those that enhance neural plasticity, are required for memory development within children. Engaging in learning encourages these signatures- which may lead to enhanced brain plasticity and facilitate future learning and cognitive development in a positive manner. As a result, the epigenome of teenagers who have had a stimulated childhood can promote gene expression that facilitates the acquisition of knowledge in a more efficient manner.
Strategies for Positive Outcomes: Policies to Induce Neurological Development within Children
It is extremely crucial to acknowledge how environmental factors may affect neurodevelopment within children in order to develop effective interventions and strategies to mitigate and avoid harmful effects that may alter a child’s life permanently or for long-term. By implementing public health policies, and educational programs, improving planned parenthood, and providing support to at-risk youth, a more favorable environment for the development of neurological processes within adolescents can be produced.
Effective children-care services can help facilitate positive learning experiences and supportive relationships- which are essential for neurodevelopment. Infants need a stable, safe, and stimulating environment while also requiring an interactive relationship with adults. In situations where toxic stress is present, early intervention is critical. Early interventions are required when children experience toxic or chronic stress within adverse environments to recognize and address the overall cause of obstacles pertaining to an adolescent’s brain development and protect the child from other harmful effects.
Conclusion
The neurodevelopment of children is the foundation of their future life and cognitive, emotional, and behavioral activities- serving as a structure upon which millions of other possible outcomes can build. This is not only shaped by a child’s genetic material but also by the environment they’ve grown up in based on epigenetic research. By understanding how environmental factors affect brain development within children, strategies to induce neurological development for adolescents can be implemented to encourage the healthy neurodevelopment of upcoming generations.
References
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