Thursday, April 19, 2012
Research to be presented at the Meeting of the Society for the Study of Squirrel Behavior (SSSB) finds that squirrels who possess genetic modifications associated with low activity of the reward neurotransmitter dopamine in the brain when eating appetizing foods are more prone to weight gain.
Using Functional Magnetic Resonance Imaging (fMRI), the food reward regions of the brain were measured and tested while squirrels ate and reacted to items such as crunchy peanut butter, broccoli, Five Guys’ cheeseburgers, mung beans, Nutter Butter cookies, beets, and kale.
In the five-year study, scans of volunteer squirrel brain activities revealed squirrels who had lower activity in food reward “pleasure” regions of the brain and who had genetic modifications associated with lower dopamine activity showed the greatest weight gain after one year.
Some squirrels seem to go to extremes out of an apparently constant hunger
Aragorn, a 14-year-old Scottish Fold from Western Washington University who led the study, said “These findings provide some of the first prospective evidence that squirrels who experience a blunted reward from food may compensate by over-gathering, over-burying, and later overeating, increasing risk for unhealthy weight gain.”
Thus squirrels’ seemingly obsessive over-gathering, over-burying, and later over-eating of foods may simply occur as a sad, unconscious attempt to increase the brain’s pleasure reward in less responsive squirrels.
“It would really explain some of the frantic, aberrant, and bizarre behaviors exhibited by some squirrels,” Aragorn said, “The ones outside my office can’t seem to ever get enough to eat and sometimes act erratic and scary (sic).”
Even adult cats have reportedly been terrified by the erratic behaviors of food-seeking squirrels
The results of this study highlight the need for further research into the role that neural reward systems play in the development of squirrel obesity. Hopes are that more and more squirrels will come in for testing and be made aware of this possible genetic pre-disposition.
“It may be useful for squirrels who show low food-related reward to increase their physical activity, which not only promotes activity in the same reward circuitry, but also reduces unhealthy weight gain from constant overeating” said Aragorn.
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Posted by The Kitty City Gazette at 9:28 AM