Harwood-Gross, A., Lambez, B., Feldman, R., Zagoory-Sharon, O., & Rassovsky, Y. (2021). The Effect of Martial Arts Training on Cognitive and Psychological Functions in At-Risk Youths. Frontiers in pediatrics, 9, 707047. https://doi.org/10.3389/fped.2021.707047
- Preliminary Definitions
- Big Three Neurotransmitters: All are monoamines (single amine group in their structure), can be affected by antidepressant medications, play overlapping roles in mood and mental health, and are made from amino acid precursors
- Serotonin ("happiness neurotransmitter"):
- Chemical class: Indolamine (derived from the amino acid tryptophan)
- Primary roles: Mood regulation, sleep, appetite, digestion
- About 90% is actually produced in the gut, not the brain
- Norepinephrine (also called noradrenaline):
- Chemical class: Catecholamine (like dopamine)
- Primary roles: Alertness, arousal, attention, fight-or-flight response
- Acts as both a neurotransmitter in the brain AND a hormone in the body
- Key player in stress response and focus
- Imbalances linked to depression, anxiety, ADHD
- Dopamine (reward neurotransmitter"):
- Chemical class: Catecholamine
- Primary roles: Reward, motivation, motor control, pleasure
- Often called the "reward neurotransmitter"
- Critical for movement (Parkinson's involves dopamine loss)
- Central to addiction, learning, and goal-seeking behavior
- Abnormalities in the neurotransmitters: seoronin, dopamine and norepinephrine. It is also associated with:
- Impaired neurodegeneration
- Neurodegeneration:
- The progressive loss, damage, or death of neurons
- Examples: Alzheimer's disease, Parkinson's disease, ALS
- "Impaired neurodegeneration" would actually mean the damage process is slowed or blocked (which would be good)
- Neuronal plasticity (or neuroplasticity):
- The brain's ability to reorganize and adapt throughout life
- Includes strengthening or weakening connections between neurons
- Allows learning, memory formation, and recovery from injury
- Neurogenesis:
- The formation of new neurons from neural stem cells
- Important for learning, memory, and potentially mood regulation
- Can be influenced by exercise, stress, diet, and other factors
- Antidepressant drugs seek to increase the production of these neurotransmitters as well as inhibiting the expression of the enzyme monoamine oxidase
- Monoamine oxidase (MAO) is an enzyme that breaks down monoamine neurotransmitters in the brain and body.
- Degrades (breaks down) neurotransmitters like serotonin, dopamine, and norepinephrine
- Acts like a "cleanup crew" - removing these neurotransmitters after they've done their job
- Helps regulate the levels of these important brain chemicals
- MAO-A: Primarily breaks down serotonin and norepinephrine
- MAO-B: Primarily breaks down dopamine (and some other compounds)
- Production of the Big Three
- From the neurotransmitter production point of view, serotonin is produced both in the brain and in the gut, with the majority (95%) residing in the intestine.
- Specifically, glucose and fatty acids stimulate the release of serotonin from the duodenum.
- Duodenum: The duodenum is the first part of the small intestine, located right after the stomach. It's about 10-12 inches long and shaped like a "C."
- This is where most chemical digestion happens - the pancreas and gallbladder release digestive enzymes and bile here to break down food from the stomach. It's crucial for absorbing nutrients like iron, calcium, and B vitamins.
- The essential amino acid tryptophan is the main precursor for the production of serotonin.
- Tryptophan is an essential amino acid (a building block of protein) that your body can't make on its own, so you must get it from food.
- Your body uses tryptophan to make serotonin (the "feel-good" neurotransmitter) and melatonin (which regulates sleep).
- This amino acid is not produced in the body, so it is necessary to obtain it through dietary sources such as: bananas, pumpkin seeds, soybeans, chickpeas, dried dates, peanuts, milk, meat, fish, turkey, and protein-rich foods.
- Oxidative Energy (same as aerobic activity): Oxidative energy refers to the process your body uses to produce ATP (cellular energy) by using oxygen to break down nutrients - primarily fats and carbohydrates. This happens in the mitochondria (the "powerhouses" of your cells).
- This is different from anaerobic energy systems (like sprinting) that work without oxygen but burn out quickly. Oxidative energy is your body's main energy system for most of daily life and endurance activities.