Two “fear centers” are the most altered brain regions between wild and domestic rabbits. Domestic rabbits have smaller amygdalae (emotion-processing centers that play a key role in the fight-or-flight response) and larger medial prefrontal cortices (thought to be involved in social behavior) than wild rabbits, an international group of researchers report online June 25 in the Proceedings of the National Academy of Sciences.
Changes to the brain regions may have produced animals less fearful of humans.
Transparent images of rabbit brains illustrate that a wild rabbit, left, has larger amygdalae (yellow) and a smaller medial prefrontal cortex (blue) than a domestic rabbit, right. Those parts of the brain may have changed during domestication because they are involved in fear.