A team at Washington State University studied cannabis-seeking behaviour in rats and published the results in Neuropsychopharmacology. They created a behavioural profile for each animal, testing social behaviour, sex, cognition, reward and arousal. For three weeks, rats were observed one hour daily, and each could nose-poke to release three seconds of cannabis vapor in an airtight chamber. Students recorded the number of nose-pokes.
The researchers measured baseline corticosterone, the rodent equivalent of human cortisol, and found a direct correlation: rats with higher natural corticosterone self-administered more cannabis. Short-term stress after a challenge did not show a link. The team also found that rats with lower cognitive flexibility and those relying on visual cues showed stronger cannabis-seeking behaviour.
Difficult words
- behaviour — Actions and reactions of animals or people.
- cognition — Mental processes like thinking and remembering.
- corticosterone — A hormone in rodents similar to cortisol.
- correlation — A relationship between two measured things.
- self-administer — Give a drug to oneself without help.self-administered
- cognitive flexibility — Ability to change thinking or behaviour.
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- Which of the tested behaviours (social behaviour, sex, cognition, reward, arousal) do you think best predicts drug seeking? Why?
- How could the finding about visual cues help design ways to reduce drug-seeking behaviour?
- Do you think short-term stress affects drug use in people the same way it did in the rats? Explain briefly.
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