0 a rat (= an animal like a large mouse) that is used in a scientific experiment:
Lab rats with electrodes implanted in their brains will repeatedly press a bar to get electrical stimulation.
When lab rats sleep, their brains revisit the maze they navigated during the day.
We can't really use him as a lab rat to figure out why this happened.
If a doctor knows you're well informed you're less likely to become a lab rat.
He says the plant is useful as a lab rat because it is small and goes to seed in a matter of days.
Bonnethead sharks are scrutinized by so many marine biologists that Chapman joked they're known as the "lab rats of the shark world."