Dog breeders have been
shaping the way the animals look and behave for centuries. That meddling in
canine evolution has sculpted dogs’ brains, too.
A brain-scanning study of 62 purebred dogs representing 33 breeds reveals that
dog brains are not all alike —
offering a starting point for understanding how brain anatomy relates to
behavior. Different breeds had different shapes of
various brain regions, distinctions that were not simply the result of head
shape or the size of the dogs’ brains or bodies, researchers report September 2
in the Journal of Neuroscience.
Through selective breeding,
“we have been systematically shaping the brains of another species,” Erin
Hecht, an evolutionary neuroscientist at Harvard University, and colleagues
The MRI scans were taken of
dogs with normal brain anatomy at the Veterinary Teaching Hospital at the
University of Georgia at Athens. While the study wasn’t designed to directly
link brain shape to behavior, the results offer some hints. Researchers
identified groups of brain areas, such as smell and taste regions, that showed
the most variability between breeds. Those groups are involved in specialized behaviors
that often serve humans, such as hunting by smell, guarding and providing companionship
to people, earlier studies have suggested.
The authors assumed the dogs
in the study were all pets. It’s possible that dogs extensively trained for specialized
work — such as sheep herding, bomb detecting or guiding the blind — might have
even more distinct brains.