activate: (in biology) To turn on, as with a gene or chemical reaction.
addiction: The National Institute of Drug Abuse defines this as a complex chronic disorder that is characterized by a difficult-to-control compulsion to use some drug, despite knowing that it will likely have harmful impacts. A first exposure to these drugs is usually voluntary. But repeated use of certain ones, NIDA explains, can create “changes to brain circuits involved in rewards, stress, and self-control.” Those changes can make it very hard to resist the urge to continue using drugs. The term has also been expanded to some behaviors that become dangerous and/or excessive, such as gambling, shopping and video game use.
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.
aversive learning: A quick-forming, and long-lasting loathing to the sight, smell or taste of some particular food. It develops after getting sick a short while after eating that food. It can show up after a single instance of linking some food with getting sick — even if the stomach upset or other symptoms didn’t start to show up for several hours.
bacteria: (singular: bacterium) Single-celled organisms. These dwell nearly everywhere on Earth, from the bottom of the sea to inside other living organisms (such as plants and animals). Bacteria are one of the three domains of life on Earth.
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.
circuit: A network that transmits electrical signals. In the body, nerve cells create circuits that relay electrical signals to the brain. In electronics, wires…
Read the full article here