Study suggests nicotine addiction might be controlled by influencing brain mechanisms

December 08, 2007

Boca Raton, FL, December 8, 2007 -There is a clear link between GABA - a chemical substance of the central nervous system that inhibits neurons in the brain - and nicotine dependence, according to a study presented today at the American College of Neuropsychopharmacology (ACNP) annual meeting. Researchers discovered that nicotine has significant effects on brain GABA, a finding which could potentially help curb the pleasurable effects of nicotine and help people break their addiction to it.

"We found that GABA may provide a very useful target for nicotine addiction therapies," said Graeme Mason, Ph.D., associate professor in the Magnetic Resonance Research Center in the Departments of Diagnostic Radiology and Psychiatry at Yale University School of Medicine and an ACNP member. "GABA is just one of a complex network of actors that promotes addiction, and we're hoping that this research will ultimately lead us to ways to help people quit smoking."

Mason sought to discover whether the enjoyable effects associated with smoking could be reduced in some way. When people use nicotine they may experience a sensation of reward, diminished anxiety, or a belief that they can focus more clearly or learn more easily. Researchers wanted to explore how a specific type of neuron that releases dopamine, a chemical that has been associated with pleasure, can prolong and intensify the pleasurable effects of nicotine. Although GABA inhibits those neurons, nicotine works against the ability of GABA to inhibit dopamine neurons after about 20 minutes, so the gratifying effects of nicotine are prolonged.

Researchers gave people who smoked regularly nicotine inhalers that deliver the same amount of the drug as in one cigarette. The amount of GABA in the subjects' brains rose about 10%, but the brain was found to make GABA four times faster after using the inhalers, and the rate of new GABA generation remained high for at least 45 minutes. In other words, keeping the supply of GABA levels high has the potential to reduce the pleasurable effects of smoking, in terms of duration and intensity.

"While GABA is probably not the root of nicotine addiction, it is part of a complex network of actors that are involved in addiction," Mason says.

Another study presented at the ACNP annual meeting which explored the role of GABA, genetics and environmental factors in smoking found that tobacco addiction is at least 50% determined by genetics. For this reason, researchers may be able to identify individuals who are vulnerable to nicotine dependence, and then implement prevention strategies accordingly.

For this study, Ming Li, Ph.D., Professor of Genetics in Psychiatry and Neurosciences at the University of Virginia recruited more than 2000 participants representing more than 600 families of smokers. They examined different regions on various chromosomes that showed linkage to nicotine addiction. Then they searched for susceptibility genes within these regions that appear to be associated with addiction. Some of these are the GABA-B receptor subunit 2 (GABAB2) gene on chromosome 9, and the GABA-A receptor-associated protein (GABARAP) gene on chromosome 17.

Li says the research could have significant public health implications because it could help curb smoking rates since researchers may be able to predict who is more prone to nicotine addiction. Tobacco is one of the most widely used substances; it kills more than 435,000 Americans each year, and despite increasing public awareness of the health risks associated with its use, little reduction in smoking prevalence has been achieved nationwide in recent years.
-end-
ACNP, founded in 1961, is a professional organization of more than 700 leading scientists, including four Nobel Laureates. The mission of ACNP is to further research and education in neuropsychopharmacology and related fields in the following ways: promoting the interaction of a broad range of scientific disciplines of brain and behavior in order to advance the understanding of prevention and treatment of disease of the nervous system including psychiatric, neurological, behavioral and addictive disorders; encouraging scientists to enter research careers in fields related to these disorders and their treatment; and ensuring the dissemination of relevant scientific advances.

American College of Neuropsychopharmacology

Related Smoking Articles from Brightsurf:

Smoking rates falling in adults, but stroke survivors' smoking rates remain steady
While the rate of Americans who smoke tobacco has fallen steadily over the last two decades, the rate of stroke survivors who smoke has not changed significantly.

What is your risk from smoking? Your network knows!
A new study from researchers at Penn's Annenberg School for Communication found that most people, smokers and non-smokers alike, were nowhere near accurate in their answers to questions about smoking's health effects.

Want to quit smoking? Partner up
Kicking the habit works best in pairs. That's the main message of a study presented today at EuroPrevent 2019, a scientific congress of the European Society of Cardiology (ESC).

Smoking and mortality in Asia
In this analysis of data from 20 studies conducted in China, Japan, South Korea, Singapore, Taiwan and India with more than 1 million participants, deaths associated with smoking continued to increase among men in Asia grouped by the years in which they were born.

Predictors of successfully quitting smoking among smokers registered at the quit smoking clinic at a public hospital in northeastern Malaysia
In the current issue of Family Medicine and Community Health, Nur Izzati Mohammad et al. consider how cigarette smoking is one of the risk factors leading to noncommunicable diseases such as cardiovascular and respiratory system diseases and cancer.

Restaurant and bar smoking bans do reduce smoking, especially among the highly educated
Smoking risk drops significantly in college graduates when they live near areas that have completely banned smoking in bars and restaurants, according to a new study in the American Journal of Epidemiology.

How the UK smoking ban increased wellbeing
Married women with children reported the largest increase in well-being following the smoking bans in the UK in 2006 and 2007 but there was no comparable increase for married men with children.

Smoking study personalizes treatment
A simple blood test is allowing Vanderbilt University Medical Center (VUMC) researchers to determine which patients should be prescribed varenicline (Chantix) to stop smoking and which patients could do just as well, and avoid side effects, by using a nicotine patch.

A biophysical smoking gun
While much about Alzheimer's disease remains a mystery, scientists do know that part of the disease's progression involves a normal protein called tau, aggregating to form ropelike inclusions within brain cells that eventually strangle the neurons.

A case where smoking helped
A mutation in the hemoglobin of a young woman in Germany was found to cause her mild anemia.

Read More: Smoking News and Smoking Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.