Bad Habits Hard-Wired in the Brain

Three weeks into 2016 and many resolutions are as stale as a bottle of champagne left open after a New Year’s party. Everyone has some kind of self-destructive behavior we’d be better off without, be it smoking or an unhealthy diet. Bad habits are hard to break, but why is that?

According to new research by Duke University researchers, our vices are hard-wired in a region of brain responsible for compulsive behavior and addiction, leaving an enduring mark that pushes us to succumb to our cravings. The greater the change in the brain circuitry, the more difficult it is to kick a habit.

For their study, published today in the journal Neuron, the Duke scientists analyzed the brains of mice who developed a sugar dependency and compared those with otherwise healthy mice. The rodents developed the habit by pressing a small lever to receive a sugary treat. After the sweets were taken away, the sugar-addicted mice continued pressing the lever even without the reward.

Within the brain is an area known as the basal ganglia, which is responsible for motor action and compulsive behaviors. Two pathways in the basal ganglia carry separate, opposing messages, “stop” and “go.”

For the mice who formed a sugar dependency, the researchers were surprised to find both the “stop” and “go” signals ramped up in the brain compared with ordinary mice.

The timing of the activation of these pathways differed in the two groups as well. For the mice that formed the habit, the go pathway lit up before stop. The opposite pattern emerged in the other test group. The head start given to the go pathway could explain difficulties in self control for those working to correct compulsive behaviors.

Encouraged by the researchers, some mice were able to break the habit when the scientists rewarded only the rodents who stopped pressing the lever, though the mice most able to do this were the ones with the weaker go pathways.

Knowing the influence of addictive, self-destructive behaviors on brain circuitry could lead to treatments to break them, such as transcranial magnetic stimulation, or using harmless magnetic pulses to stimulate the brain, an avenue some researchers have already begun exploring.

Read more at Discovery News