A catecholamine hormone produced by the adrenal glands and some neurons. Adrenaline, also known as epinephrine, exerts many effects in the body, the most notable being those associated with the “fight or flight” response to stressors. The effects of epinephrine and norepinephrine (a related catecholamine) are mediated by adrenergic receptors, which act as the interface between the sympathetic nervous system and the cardiovascular system.

A mood disorder characterized by profound sadness, fatigue, altered sleep and appetite, as well as feelings of guilt or low self-worth. Depression is often accompanied by perturbations in metabolic, hormonal, and immune function. A critical element in the pathophysiology of depression is inflammation. As a result, elevated biomarkers of inflammation, including the proinflammatory cytokines interleukin-6 and tumor necrosis factor-alpha, are commonly observed in depressed people. Although selective serotonin reuptake inhibitors and cognitive behavioral therapy typically form the first line of treatment for people who have depression, several non-pharmacological adjunct therapies have demonstrated effectiveness in modulating depressive symptoms, including exercise, dietary modification (especially interventions that capitalize on circadian rhythms), meditation, sauna use, and light therapy, among others.

A region of the forebrain below the thalamus that coordinates both the autonomic nervous system and the activity of the pituitary, controlling body temperature, thirst, hunger, and other homeostatic systems, and involved in sleep and emotional activity.

A critical element of the body’s immune response. Inflammation occurs when the body is exposed to harmful stimuli, such as pathogens, damaged cells, or irritants. It is a protective response that involves immune cells, cell-signaling proteins, and pro-inflammatory factors. Acute inflammation occurs after minor injuries or infections and is characterized by local redness, swelling, or fever. Chronic inflammation occurs on the cellular level in response to toxins or other stressors and is often “invisible.” It plays a key role in the development of many chronic diseases, including cancer, cardiovascular disease, and diabetes.

An essential mineral present in many foods. Iron participates in many physiological functions and is a critical component of hemoglobin. Iron deficiency can cause anemia, fatigue, shortness of breath, and heart arrhythmias.

A chemical that causes Parkinson's disease-like symptoms. MPTP undergoes enzymatic modification in the brain to form MPP+, a neurotoxic compound that interrupts the electron transport system of dopaminergic neurons. MPTP is chemically related to rotenone and paraquat, pesticides that can produce parkinsonian features in animals.

A substance produced in the brain. Norepinephrine acts as a hormone and neurotransmitter and is best known for its role in the body’s “fight or flight” response to stress. Its role as a neurotransmitter has been exploited as a molecular target for a class of drugs known as norepinephrine reuptake inhibitors, which were developed for the purpose of treating disorders ranging from ADHD to narcolepsy and depression. Norepinephrine also plays a role in converting white adipose tissue into brown adipose tissue via an uncoupling protein 1 (UCP-1) mediated mechanism.

A small endocrine gland found in the brain of mammals. The pineal gland secretes melatonin, a hormone that regulates the sleep-wake cycle as well as other metabolic processes.

The highest level of intake of a given nutrient likely to pose no adverse health effects for nearly all healthy people. As intake increases above the upper intake level, the risk of adverse effects increases.