Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tobacco smoking impacts teens' brains

03.03.2011
Less activity found in prefrontal cortex, the 'executive center' of brain
Tobacco smoking is the leading preventable cause of death and disease in the U.S., with more than 400,000 deaths each year attributable to smoking or its consequences. And yet teens still smoke. Indeed, smoking usually begins in the teen years, and approximately 80 percent of adult smokers became hooked by the time they were 18. Meanwhile, teens who don't take up smoking usually never do.

While studies have linked cigarette smoking to deficits in attention and memory in adults, UCLA researchers wanted to compare brain function in adolescent smokers and non-smokers, with a focus on the prefrontal cortex, the area of the brain that guides "executive functions" like decision-making and that is still developing structurally and functionally in adolescents.

They found a disturbing correlation: The greater a teen's addiction to nicotine, the less active the prefrontal cortex was, suggesting that smoking can affect brain function.

The research appears in the current online edition of the journal Neuropsychopharmacology.

The finding is obviously not good news for smokers, said the study's senior author, Edythe London, a professor of psychiatry at the Semel Institute for Neuroscience and Human Behavior at UCLA.

"As the prefrontal cortex continues to develop during the critical period of adolescence, smoking may influence the trajectory of brain development and affect the function of the prefrontal cortex," London said.

In the study, 25 smokers and 25 non-smokers between the ages of 15 to 21 were asked to perform a test that activated the prefrontal cortex and required them to inhibit responding.

The test, called the Stop-Signal Task (SST), was done while the participants were undergoing functional magnetic resonance imaging (fMRI). The Stop-Signal Task involves pressing a button as quickly as possible every time a lighted arrow appears — unless an auditory tone is played, in which case the participant must prevent himself from pressing the button. It is a test of a person's ability to inhibit an action.

Prior to the fMRI test, the researchers used the Heaviness of Smoking Index (HSI) to measure the level of nicotine dependence in the smoking group. The HSI takes into account how many cigarettes a teen smokes in a day and how soon after waking he or she takes the first smoke.

The results of the tests, London said, were interesting — and surprising. Among smokers, the researchers found that the higher the HSI — that is, the more a teen smoked — the lesser the activity in the prefrontal cortex. And yet, despite these lower levels of activation, the smoking group and the non-smoking group performed roughly the same with respect to inhibition on the Stop-Signal Task.

"The finding that there was little difference on the Stop-Signal Task between smokers and non-smokers was a surprise," said London, who is also a professor of molecular and medical pharmacology at the David Geffen School of Medicine at UCLA and a member of the UCLA Brain Research Institute. "That suggested to us that the motor response of smokers may be maintained through some kind of compensation from other brain areas."

Protracted development of the prefrontal cortex has been implicated as a cause of poor decision-making in teens, London said, caused by immature cognitive control during adolescence.

"Such an effect can influence the ability of youth to make rational decisions regarding their well-being, and that includes the decision to stop smoking," she said.

The key finding, London noted, is that "as the prefrontal cortex continues to develop during the critical period of adolescence, smoking may influence the trajectory of brain development, affecting the function of the prefrontal cortex. In turn, if the prefrontal cortex is negatively impacted, a teen may be more likely to start smoking and to keep smoking — instead of making the decision that would favor a healthier life."

On the other hand, the fact that adolescent smokers and non-smokers performed equally well during a response-inhibition test suggests that early interventions during the teen years may prevent the transition from a teen smoking an occasional cigarette in response to peer pressure to addiction in later adolescence.

In addition to London, study authors included lead author Adriana Galván, Christine M. Baker and Kristine M. McGlennen of UCLA, and Russell A. Poldrack, of the University of Texas at Austin.

Funding for this study was provided by Philip Morris USA, an endowment from the Thomas P. and Katherine K. Pike Chair in Addiction Studies, and a gift from the Marjorie M Greene Trust. None of the sponsors had any involvement in the design, collection, analysis or interpretation of data, the writing the manuscript, or the decision to submit the manuscript for publication.

The Semel Institute for Neuroscience and Human Behavior is an interdisciplinary research and education institute devoted to the understanding of complex human behavior, including the genetic, biological, behavioral and sociocultural underpinnings of normal behavior, and the causes and consequences of neuropsychiatric disorders. In addition to conducting fundamental research, the institute faculty seeks to develop effective strategies for prevention and treatment of neurological, psychiatric and behavioral disorder, including improvement in access to mental health services and the shaping of national health policy.

For more news, visit the UCLA Newsroom and follow us on Twitter.

Mark Wheeler | EurekAlert!
Further information:
http://www.ucla.edu

More articles from Health and Medicine:

nachricht Satellites, airport visibility readings shed light on troops' exposure to air pollution
09.12.2016 | Veterans Affairs Research Communications

nachricht Oxygen can wake up dormant bacteria for antibiotic attacks
08.12.2016 | Penn State

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>