addiction: (v. addicted; adj. addictive) The National Institute of Drug Abuse defines this as a complex chronic disease that is “characterized by drug seeking and use that is compulsive, or difficult to control, despite harmful consequences.” A first exposure to drugs is usually voluntary. But repeated use of certain drugs, NIDA explains, can create changes in the brain that make it hard “to resist intense urges to take drugs.”
adolescence: A transitional stage of physical and psychological development that begins at the onset of puberty, typically between the ages of 11 and 13, and ends with adulthood. Someone undergoing this transition is known as an adolescent.
amygdala: An area deep within the brain and near the temporal lobe. Among other things, the amygdala plays a role in emotions. The term comes from the Greek word for an almond, which this region resembles in shape.
anxiety: A nervous reaction to events causing excessive uneasiness and apprehension. People with anxiety may even develop panic attacks.
axon: The long, tail-like extension of a neuron that conducts electrical signals away from the cell.
behavior: The way something, often a person or other organism, acts towards others, or conducts itself.
binge drink: To consume a dangerous amount of alcohol in a short period of time. At a minimum, this would be five servings by an adult within a single day, usually within a short period of time. For teens, it could take far less alcohol to constitute binging.
cell: (in biology) The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells. Most organisms, such as yeasts, molds, bacteria and some algae, are composed of only one cell.
chemistry: The field of science that deals with the composition, structure and properties of substances and how they interact. Scientists use this knowledge to study unfamiliar substances, to reproduce large quantities of useful substances or to design and create new and useful substances.
dendrites: Hair-like projections from the head (cell body) of a neuron. They sit ready to catch a neurotransmitter, a chemical signal, that has been released by a neighboring neuron.
depression: (in medicine) A mental illness characterized by persistent sadness and apathy. Although these feelings can be triggered by events, such as the death of a loved one or the move to a new city, that isn’t typically considered an “illness” — unless the symptoms are prolonged and harm an individual’s ability to perform normal daily tasks (such as working, sleeping or interacting with others). People suffering from depression often feel they lack the energy needed to get anything done. They may have difficulty concentrating on things or showing an interest in normal events. Many times, these feelings seem to be triggered by nothing; they can appear out of nowhere.
develop: (n. development) To emerge or to make come into being, either naturally or through human intervention, such as by manufacturing. (in biology) To grow as an organism from conception through adulthood, often undergoing changes in chemistry, size, mental maturity or sometimes even shape.
dopamine: A neurotransmitter, this chemical helps transmit signals in the brain.
e-cigarette: (short for electronic cigarette) Battery-powered device that disperses nicotine and other chemicals as tiny airborne particles that users can inhale. They were originally developed as a safer alternative to cigarettes that users could use as they tried to slowly break their addiction to the nicotine in tobacco products. These devices heat up a flavored liquid until it evaporates, producing vapors. People use these devices are known as vapers.
fiber: Something whose shape resembles a thread or filament.
field: An area of study, as in: Her field of research is biology. Also a term to describe a real-world environment in which some research is conducted, such as at sea, in a forest, on a mountaintop or on a city street. It is the opposite of an artificial setting, such as a research laboratory.
formaldehyde: A widely used and toxic chemical that manufacturers add to plastics, resins, some fertilizers, dyes, medicines and embalming fluids. It’s even in the treatments used to keep fabrics from wrinkling.
gene: (adj. genetic) A segment of DNA that codes, or holds instructions, for a cell’s production of a protein. Offspring inherit genes from their parents. Genes influence how an organism looks and behaves.
genetic: Having to do with chromosomes, DNA and the genes contained within DNA. The field of science dealing with these biological instructions is known as genetics. People who work in this field are geneticists.
immune: (adj.) Having to do with immunity.
inference: A conclusion or deduction based on evidence, data, observations or similar situations.
inflammation: (adj. inflammatory) The body’s response to cellular injury and obesity; it often involves swelling, redness, heat and pain. It also is an underlying feature responsible for the development and aggravation of many diseases, especially heart disease and diabetes.
link: A connection between two people or things.
mental health: A term for someone’s emotional, psychological and social well-being. It refers to how people behave on their own and how they interact with others. It includes how people make choices, handle stress and manage fear or anxiety. Poor mental health can be triggered by disease or merely reflect a short-term response to life’s challenges. It can occur in people of any age, from babies to the elderly.
microglia: A type of cell found in the brain and spinal cord. It can move from place to place, and serve as part of the immune system, protecting the brain from infection.
network: A group of interconnected people or things.
neuron: The main cell type of the nervous system — the brain, spinal column and nerves. These specialized cells transmit information by producing, receiving and conducting electrical signals. Neurons also can transmit signals to other cells with chemical messengers.
neuroscientist: Someone who studies the structure or function of the brain and other parts of the nervous system.
neurotransmitter: A chemical released at the end of a neuron to carry a message to a neighboring cell. This chemical travels across the space between two cells, and then binds to molecules on a neighboring cell to transmit a message. Neurotransmitters are released from neurons and can bind to neurons or to other types of cell, including those that make up muscles or glands.
nicotine: A colorless, oily chemical produced in tobacco and certain other plants. It creates the “buzz” associated with smoking. Highly addictive, nicotine is the substance that makes it hard for smokers to give up their use of cigarettes. The chemical is also a poison, sometimes used as a pesticide to kill insects and even some invasive snakes or frogs.
nucleus accumbens: An area deep within the front part of the brain that is linked to pleasure and motivation.
potent: An adjective for something (like a germ, poison, drug or acid) that is very strong or powerful.
psychiatrist: A medical doctor who spends many years learning to study and treat diseases of the human mind. Treatments may consist of talking therapies, prescription drugs or both. This medical field is known as psychiatry.
receptor: (in biology) A molecule in cells that serves as a docking station for another molecule. That second molecule can turn on some special activity by the cell.
reward system: (Also reward center) A region of the brain that processes the pleasant reactions we get when we get smiles, gifts, pleasurable stimuli (including food) or compliments.
salt: A compound made by combining an acid with a base (in a reaction that also creates water).
smoking: A term for the deliberate inhalation of tobacco smoke from burning cigarettes.
stress: (in biology) A factor — such as unusual temperatures, movements, moisture or pollution — that affects the health of a species or ecosystem. (in psychology) A mental, physical, emotional or behavioral reaction to an event or circumstance (stressor) that disturbs a person or animal’s usual state of being or places increased demands on a person or animal; psychological stress can be either positive or negative.
symptom: A physical or mental indicator generally regarded to be characteristic of a disease. Sometimes a single symptom — especially a general one, such as fever or pain — can be a sign of any of many different types of injury or disease.
synapse: The junction between neurons that transmits chemical and electrical signals.
system: A network of parts that together work to achieve some function. For instance, the blood, vessels and heart are primary components of the human body’s circulatory system. Similarly, trains, platforms, tracks, roadway signals and overpasses are among the potential components of a nation’s railway system. System can even be applied to the processes or ideas that are part of some method or ordered set of procedures for getting a task done.
vaping: (v. to vape) A slang term for the use of e-cigarettes because these devices emit vapor, not smoke. People who do this are referred to as vapers.
