New research shows that inhibiting a certain protein in the brain lessens the amount of anxiety reduction due to nicotine use.
One of the reasons people continue to smoke after trying it just once or twice is the dampening of anxiety that occurs as a result of nicotines influence on the brain. Now, researchers from the Salk Institute for Biological Studies show in their paper published in the Journal of Neuroscience that removing a certain type of protein in the brain blocks the rewarding effects of nicotine. This new research provides further insights into how nicotine affects the brain, and will hopefully lead to new therapies to help people stop smoking.
How Nicotine Affects the Brain
Researchers believe that nicotine affects the brain by binding with protein receptors that lie on top of brain cells. These are the very same cells that are responsible for producing dopamine, the chemical that is known to cause feelings of euphoria. Though the researchers also acknowledge that they still arent sure just yet how dopamine is both able to produce feelings of euphoria and repression of anxiety, they suggest it has something to do with blocking alpha4 receptors in certain parts of the brain responsible for motivation, emotion and addiction.
The team, led by Tresa McGranahan, Stephen Heinemann, and T. K. Booker, found they were able to effectively shut down the mechanism in the brain that leads to lessening of anxiety, by breeding mice that had an alpha4 mutation in just dopamine producing cells. The net impact was the absence of the protein in the cells. Experiments in the lab showed that this decreased the anxiety reducing effect of nicotine in the mice when given nicotine.
How the New Research Could Lead to Nicotine Addiction Treatment
Because the human brain is thought to react the same way to nicotine as the mouse brain, the researchers are optimistic that a drug could be developed to dampen the alpha4 receptors responsible for the interactions with nicotine. This would result in the lessening of feelings of anxiety that keep people smoking even though they know about the adverse health effects. Whether the same drug would also assist in a reduction of withdrawal symptoms is less clear, as the mechanism that leads to such cravings are thought to be based on different mechanisms in the brain.
Another difficult problem is developing a drug that would work only on the alpha4 receptors that create dopamine while leaving other receptors alone. There could otherwise be unexpected side effects that could negatively impact the person to such an extent that they would refuse the treatment.