Brusini, Irene, Carneiro, Miguel, Wang, Chunliang, Rubin, Carl-Johan, Ring, Henrik, Afonso, Sandra, Blanco-Aguiar, José Antonio, Ferrand, Nuno, Rafati, Nima, Villafuerte, Rafael, Smedby, Örjan, Damberg, Peter, Hallböök, Finn, Fredrikson, Mats, Andersson, Leif, Ministério da Ciência, Tecnologia e Ensino Superior (Portugal), Swedish Research Council, Knut and Alice Wallenberg Foundation, Fundação para a Ciência e a Tecnologia (Portugal), Swedish Brain Foundation, Programa Operacional do Potencial Humano (Portugal), Quadro de Referência Estratégico Nacional (Portugal), and European Commission
The most characteristic feature of domestic animals is their change in behavior associated with selection for tameness. Here we show, using high-resolution brain magnetic resonance imaging in wild and domestic rabbits, that domestication reduced amygdala volume and enlarged medial prefrontal cortex volume, supporting that areas driving fear have lost volume while areas modulating negative affect have gained volume during domestication. In contrast to the localized gray matter alterations, white matter anisotropy was reduced in the corona radiata, corpus callosum, and the subcortical white matter. This suggests a compromised white matter structural integrity in projection and association fibers affecting both afferent and efferent neural flow, consistent with reduced neural processing. We propose that compared with their wild ancestors, domestic rabbits are less fearful and have an attenuated flight response because of these changes in brain architecture., The study was funded by the Knut and Alice Wallenberg foundation (L.A.), the Swedish Research Council (L.A. and M.F.), the Swedish Brain Foundation (M.F.), and POPH-QREN funds from the European Social Fund and Portuguese Ministry of Science, Technology and Higher Education (FCT Investigator Programme IF/00283/2014/CP1256/CT0012 and Postdoctoral Grant SFRH/BPD/65464/2009, to J.A.B.-A.)