Table 1.
Glossary
| Term | Definition |
|---|---|
| Unconditioned stimulus (US) | Any stimulus that can trigger a response without prior learning experience |
| Conditioned stimulus (CS) | An initially neutral stimulus that gains the ability to evoke responses after being paired with an unconditioned stimulus |
| Cue fear conditioning | The process by which a discrete and salient sensory stimulus, such as a neutral tone, is paired with a noxious US, usually a mild foot shock. As a result, the CS acquires the ability to elicit the responses originally associated with the US |
| Contextual fear conditioning | The process by which a context where the animal received a noxious US acquires the ability to elicit fear responses |
| Elevated plus maze | An apparatus that consists of open and enclosed arms, used commonly for probing anxiety in rodents |
| Fear | Various types of short-lived defensive responses elicited by imminent threats. Whereas fear is accompanied by feelings of fright in humans, it is unclear whether animals also experienced such states |
| Anxiety | Various types of enduring responses elicited by diffuse and uncertain treats. Whereas anxiety is accompanied by feelings of dread in humans, it is unclear whether animals also experienced such states |
| Anxiogenic | Stimulus or process that promotes anxiety |
| Anxiolytic | Stimulus or process that reduces anxiety |
| Fear-potentiated startle | A paradigm where fear is assessed by measuring startle responses elicited by loud noise bursts. After CS-footshock pairings, noise bursts presented during the CS elicit higher startle responses |
| Cue-induced reinstatement | In drug dependence experiments, animals are often trained to lever press for drug self-administration when cued with the presentation of a light and tone compound stimulus. Following self-administration, animals undergo an extinction period where lever responses decrease but do not completely disappear. Next, in cue-induced reinforcement, reintroduction of the light-tone CS results in an increase of lever presses, even though no drug is delivered in this part of the experiment |