Which factors influence brain chemistry and development?

• A. Genetics
• B. Sleep, nutrition, and physical activity
• C. Nutrition, the environment, and trauma
• D. Peer relationships

Answer: (C)

Brain development and the chemicals that underlie it are shaped by what the brain gets, the experiences it has, and how it responds to stress. Nutrition supplies the building blocks for neurons, myelin, and neurotransmitters; without balanced nutrients, brain signaling and development can be disrupted. The environment provides the experiences that sculpt neural connections—caregiving, play, learning opportunities, and sensory input all influence how brain circuits wire together and how plastic they remain. Trauma adds another layer by activating the body's stress response, which can alter hormone levels and chemistries in key brain regions like the amygdala, hippocampus, and prefrontal cortex, affecting emotion regulation, attention, and executive function. Taken together, these factors explain meaningful ways brain chemistry and development are shaped beyond genetics, making nutrition, the environment, and trauma essential influences.