Brain morphology of wild and domestic rabbits differs remarkably

An international research team led by Leif Andersson (Uppsala University/SciLifeLab) has studied how domestication has affected brain morphology in rabbits. The results, published in PNAS, show significant differences in brain morphology between domesticated and wild individuals. Brain regions involved in fear processing, the amygdala and medial prefrontal cortex were particularly affected. 

The most characteristic feature of domestic animals is their tame behavior. In contrast to domestic rabbits, wild rabbits have a very strong flight response because they are hunted by predators.

To compare the brains of domestic and wild rabbits, the scientists behind the study raised eight domestic and eight wild rabbits under very similar conditions to minimize changes due to environmental effects. Using high-resolution magnetic resonance imaging (MRI), the researchers were then able to observe profound differences between the wild and domestic rabbits brains. The results show that domestic rabbits have a reduced amygdala while their medial prefrontal cortex is enlarged compared to wild individuals. Wild rabbits also have a larger brain-to-body size ratio and more white matter than domestic ones, which suggests that domestic rabbits have a compromised information processing. This might explain why domestic rabbits are more slow reacting and phlegmatic than their wild counterparts.

‘This study is not only important for our understanding of animal domestication but also for the basic understanding how variation in brain morphology can impact a complex behavior like fear response,’ says Leif Andersson.

Read full scientific paper in PNAS

Read full press release from Uppsala University