To study the effects of nicotine addiction and related behaviors, a research team funded by the National Institute on Drug Abuse (NIDA) created a special strain of mice through a process in which researchers altered only one amino acid. This "knock-in" technology made this particular strain of mice exceptionally sensitive to nicotine.
Researchers found these mice display rather powerful addiction-related behaviors, including reward, tolerance and sensitization to the drug, that occur at remarkably low nicotine doses.
Nicotine bears a molecular resemblance to the nerve chemical acetylcholine which allows it to bind to nicotinic acetylcholine receptors on nerve cells. The act of binding causes the cells on which the receptors reside to release dopamine, a chemical involved in the brain's pleasure/reward system. Previous work has focused on creating "knock-out" mice that, due to the altered genetic structure, produce less dopamine and thus eliminate their response to nicotine.
This technique could offer a better explanation about why teenagers are more responsive to smoking and would have a harder time stopping than adults who pick up the habit later on.
Nicotine addiction is the largest cause of preventable mortality in the world, leading to more than 4 million smoking-related deaths annually, according to the NIDA. As with all addictions, the easiest way to rid yourself of them is to never start.
If you been wanting to quit, I can't think of a more effective tool you can use than the Emotional Freedom Technique (EFT). Check out my free online EFT manual that will show you how to get back on the road to better health and defeat your addictions.
Science Blog November 11, 2004