Is your rat an emotional eater?
The Daily Princetonian - Research on rats reveals connection between binge eating, food addiction: "Research on rats reveals connection between binge eating, food addiction
The side wall of psychology professor Bart Hoebel's office is lined with dozens of storage boxes. One is labeled "salt," another "self-stimulation," yet another "crave." Then there is the cluster of boxes resting prominently on top of a file cabinet, each labeled, "Food Addiction."
Food addiction — or more technically, "the neural basis of appetite" — has been the focus of Hoebel's research for the past 47 years. Initially looking to study brain mechanisms that control eating and are also involved in drug addiction, Hoebel's research led him to study whether food can be addictive.
Hoebel and his students placed rats on different feeding cycles, then observed their behavior in response to those cycles and subsequent changes in the brain.
"We had to create an animal model with an eating disorder that might reflect food addiction," he said.
His research has shown that a prolonged cycle of binge feeding on sugar induces dependency in rats by causing them to become dependent on their own natural brain opiates. The experiment involved placing rats on a cycle of no food for 12 hours, followed by 12 hours of regular food plus a sugar solution. Hence, the rats were binge feeding on sugar for alternating 12-hour spans. As time progressed, the rats consumed an increasing amount of the sugar solution.
After about three weeks, the rats experienced an increase in brain receptors for opiates and dopamine. Opiates are chemical messengers that identify sweet tastes as desirable, while dopamine is a chemical messenger that works with memory to urge people to pursue sweet tastes in the future.
When an injection of an opiate-blocker was administered, the rats experienced withdrawal symptoms, including teeth chattering, body quivering and anxiety.
The rats were essentially "getting addicted to their brains' own morphines," Hoebel said.
Another component of the study examined lasting changes in the behavior of sugar-addicted rats after ten days on a normal diet. Sugar whet the rats' appetite for chow more than usual, and the animals were hyperactive to amphetamine, a chemical that releases dopamine.
These conclusions taken together show that sugar binging can cause "lasting changes in the brain, in that sensitization remains after a period of normal feeding," Hoebel said.
Yet, as Hoebel emphasizes, "It's not just the sugar, but how and when you eat it." In rats, binge eating promotes addiction, "just like binge drinking alcohol promotes alcohol addiction."
Addiction involves three stages: increased intake of a substance, followed by withdrawal symptoms upon deprivation and signs of craving and relapse.
Hoebel's research could reveal the reasons behind food addiction in humans and could lead to more effective treatment for people with eating disorders.
In the meantime, Hoebel's advice: "If addiction runs in your family, then repeated fasting and binging on sugar or alcohol may lead to an addiction that disrupts your life. You can choose your pattern of intake now when you are young. Otherwise you may not be able to reverse the brain changes later."
Have you called Jenny yet?
The side wall of psychology professor Bart Hoebel's office is lined with dozens of storage boxes. One is labeled "salt," another "self-stimulation," yet another "crave." Then there is the cluster of boxes resting prominently on top of a file cabinet, each labeled, "Food Addiction."
Food addiction — or more technically, "the neural basis of appetite" — has been the focus of Hoebel's research for the past 47 years. Initially looking to study brain mechanisms that control eating and are also involved in drug addiction, Hoebel's research led him to study whether food can be addictive.
Hoebel and his students placed rats on different feeding cycles, then observed their behavior in response to those cycles and subsequent changes in the brain.
"We had to create an animal model with an eating disorder that might reflect food addiction," he said.
His research has shown that a prolonged cycle of binge feeding on sugar induces dependency in rats by causing them to become dependent on their own natural brain opiates. The experiment involved placing rats on a cycle of no food for 12 hours, followed by 12 hours of regular food plus a sugar solution. Hence, the rats were binge feeding on sugar for alternating 12-hour spans. As time progressed, the rats consumed an increasing amount of the sugar solution.
After about three weeks, the rats experienced an increase in brain receptors for opiates and dopamine. Opiates are chemical messengers that identify sweet tastes as desirable, while dopamine is a chemical messenger that works with memory to urge people to pursue sweet tastes in the future.
When an injection of an opiate-blocker was administered, the rats experienced withdrawal symptoms, including teeth chattering, body quivering and anxiety.
The rats were essentially "getting addicted to their brains' own morphines," Hoebel said.
Another component of the study examined lasting changes in the behavior of sugar-addicted rats after ten days on a normal diet. Sugar whet the rats' appetite for chow more than usual, and the animals were hyperactive to amphetamine, a chemical that releases dopamine.
These conclusions taken together show that sugar binging can cause "lasting changes in the brain, in that sensitization remains after a period of normal feeding," Hoebel said.
Yet, as Hoebel emphasizes, "It's not just the sugar, but how and when you eat it." In rats, binge eating promotes addiction, "just like binge drinking alcohol promotes alcohol addiction."
Addiction involves three stages: increased intake of a substance, followed by withdrawal symptoms upon deprivation and signs of craving and relapse.
Hoebel's research could reveal the reasons behind food addiction in humans and could lead to more effective treatment for people with eating disorders.
In the meantime, Hoebel's advice: "If addiction runs in your family, then repeated fasting and binging on sugar or alcohol may lead to an addiction that disrupts your life. You can choose your pattern of intake now when you are young. Otherwise you may not be able to reverse the brain changes later."
Have you called Jenny yet?
posted by Lee at 7:38 AM
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