anxious: (n. anxiety) A feeling of dread over some potential or upcoming situation, usually one over which someone feels they have little control.
behavior: The way something, often a person or other organism, acts towards others, or conducts itself.
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 typically route those signals to activate some mechanical, computational or other function.
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.
disorder: (in medicine) A condition where the body does not work appropriately, leading to what might be viewed as an illness. This term can sometimes be used interchangeably with disease.
focus: (in behavior) To look or concentrate intently on some particular point or thing.
midbrain: An area of the brain located at the top of the brain stem, in the roughly the center of the head. Areas of the midbrain play important roles in sleep, motivation, movement, body temperature and more.
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.
neuroscience: The field of science that deals with the structure or function of the brain and other parts of the nervous system. Researchers in this field are known as neuroscientists.
prejudice: From the phrase “pre-judged,” it is a usually negative attitude towards one or more people owing to their belonging to some group or holding to certain values or ideas.
rodent: A mammal of the order Rodentia, a group that includes mice, rats, squirrels, guinea pigs, hamsters and porcupines.
species: A group of similar organisms capable of producing offspring that can survive and reproduce.
ultrasound: (adj. ultrasonic) Sounds at frequencies above the range that can be detected by the human ear, usually 20,000 hertz and higher. Also it’s the name of a medical procedure that uses ultrasound to “see” within the body.
vocalization: Vocal sounds that an animal intentionally makes to communicate information.