“The domestication of plants and animals is one of the most important developments
during human history. In this study, we shed light on how this process has altered brain
function in
domestic animals
and made them tamer.”
One signi cant nding was that genes involved in dopamine signaling, a chemical
involved in fear responses, were expressed at higher rates in the amygdala, or area of the
brain associated with memory, decision-making, and emotional responses, of the
domestic rabbit. Notably, the amygdala is known as the part of the brain driving the “ ght
or ight” response, which would play a part in determining whether a wild animal
ees in
the company of humans or a tame animal tolerates human presence.
Researchers also found that genes associated with ciliary function were consistently
downregulated in the hippocampus, an area of the brain associated with learning and
memory, of domestic rabbits. Cilia cells are tiny hair-like structures that aid in the
circulation of cerebrospinal uid.
The ow of this uid contributes to the transmission of molecular signals across the
brain. Since these ciliary genes are important for brain development, the researchers
hypothesized that these changes contribute to the evolution of tameness.
“We were really surprised by the consistent changes we observed that several genes
involved in dopamine signaling were consistently unregulated in the domestic brain, and
that many genes associated with ciliary function was consistently downregulated,”
Andersson says.
Source:
Texas A&M University