Significant Neuroanatomical Variation Among Domestic Dog Breeds

• Type of Material: Article
• Authors: Erin Hecht, Emory University; Jeroen B. Smaers, SUNY Stony Brook; William D. Dunn, Emory University; Marc Kent, University of Georgia; Todd Preuss, Emory University; David Gutman, Emory University
• Language: English
• Date: 2019-09-25
• Publisher: Society for Neuroscience
• Publication Version: Final Published Version
• Copyright Statement: © 2019 the authors.
• Final Published Version (URL): http://dx.doi.org/10.1523/JNEUROSCI.0303-19.2019
• Title of Journal or Parent Work: The Journal of Neuroscience
• Volume: 39
• Issue: 39
• Start Page: 7748
• End Page: 7758
• Grant/Funding Information: Additional support was provided by NIH OD P51OD11132 to the Yerkes National Primate Research Center.; This work was supported by the National Science Foundation–Division of Integrative Organismal Systems (Grant NSF-IOS 1457291).
• Keywords: Neurosciences & Neurology; Science & Technology; morphology; Life Sciences & Biomedicine; evolution; Inference; Model; Estimating variable rates; Ability; selective breeding; Size; System; dogs; Neurosciences; canines; MRI
• Research Categories: Biology, Animal Physiology; Biology, Neuroscience; Anthropology, Physical; Biology, Anatomy

Abstract

Humans have bred different lineages of domestic dogs for different tasks such as hunting, herding, guarding, or companionship. These behavioral differences must be the result of underlying neural differences, but surprisingly, this topic has gone largely unexplored. The current study examined whether and how selective breeding by humans has altered the gross organization of the brain in dogs. We assessed regional volumetric variation in MRI studies of 62 male and female dogs of 33 breeds. Neuroanatomical variation is plainly visible across breeds. This variation is distributed nonrandomly across the brain. A whole-brain, data-driven independent components analysis established that specific regional subnetworks covary significantly with each other. Variation in these networks is not simply the result of variation in total brain size, total body size, or skull shape. Furthermore, the anatomy of these networks correlates significantly with different behavioral specialization(s) such as sight hunting, scent hunting, guarding, and companionship. Importantly, a phylogenetic analysis revealed that most change has occurred in the terminal branches of the dog phylogenetic tree, indicating strong, recent selection in individual breeds. Together, these results establish that brain anatomy varies significantly in dogs, likely due to human-applied selection for behavior.