How Nicotine Acts on the Human Brain

A new series of investigation on how nicotine affects the human brain could lead to the development of new therapies against this addiction, as well as to the creation of treatments for Parkinson's, schizophrenia, and other neurological conditions.

According to investigators, the first puff out of a cigarette should send smokers convulsing to the floor. That is because the brain proteins that nicotine influence looks remarkably similar to receptor proteins on muscle cells.

These receptors are what tell the muscles to contract. However, nicotine appears to prefer the brain over muscles, and does not send smokers convulsing to the floor.

Quite the opposite in fact, smokers say. When a cigarette is lit, it often calms the smoker, and makes them more focused on the task at hand. A team of researchers recently set out to learn why.

“Muscle proteins couldn't be very sensitive to nicotine. Because if they were, smoking would be intolerable – every puff would activate every muscle in your body,” explains Dennis Dougherty.

He holds an appointment as a chemist at the California Institute of Technology (Caltech), in Pasadena. The expert conducted the work alongside colleague and Caltech biologist Henry Lester.

The team draws attention that there are some very interesting statistics associated with smoking. While the percentage of smokers in the general population is 20 percent, more than 90 percent of schizophrenia patients smoke.

Additionally, people who are long-term smokers have been shown in previous studies to be at a 50 percent lower risk of developing Parkinson's disease. Why this correlation exists is unknown.

What nicotine does in the brain is it hijacks a family of proteins that usually binds to the neurotransmitter acetylcholine. This chemical is involved in a large number of physiological processes.

Some researchers believe that this is precisely what makes nicotine so addictive to the human brain, although no clear conclusions on this issue have yet been reached.

Further analysis in this direction could reveal the existence of neurological pathways that play an important role in diseases such as schizophrenia and Parkinson's.

Given the large number of possibilities and opportunities that investigating nicotine could provide, it stands to reason to assume that this field of research is now still in its infancy.