UNIPE 2015/2

TEXTO:

Teens and smoking

  It’s no surprise that smoking for years can change
the way the brain processes nicotine, creating a
well-worn pattern of craving and satisfaction that is
difficult to break. In the latest research, published in the
[5] journal Neuropsychopharmacology, Edythe London, a
professor of psychiatry and pharmacology at University
of California Los Angeles, and her team found that young
smokers did have differences in a specific brain region
compared with non smokers. Even more concerning,
[10] these differences emerged with a relatively light smoking
habit of one pack or less of cigarettes a day.
  London and her colleagues focused on a brain region
called insula, since previous studies in animals and
adults showed that its size and volume was affected by
[15] smoking. Of the regions in the cortical, or memory,
awareness and language parts of the brain, the insula
contains the most receptors for nicotine. The region is
responsible for decision-making and helping to establish
a person’s conscious awareness of his internal state. In
[20] studies of stroke patients, smokers who lost function of
the right insula in the stroke quit smoking, and reported
feeling no cravings for nicotine. And in earlier studies
London’s team conducted, they found a strong
relationship of how much smokers who watched videos
[25] of people smoking experienced cravings for cigarettes
and the activity of the insula, which lit up on PET scans.
  When London’s team looked at the brains of 18
smoking teens and 24 non-smoking adolescents, aged
16 to 21 years, using structural MRI, they found no
[30] differences overall in the insula region. But a closer
examination revealed that the right insula of the smokers
was thinner than those of the nonsmokers. “The brain is
still undergoing development when someone is in their
late teens,” she says. “It’s possible that smoking during
[35] this period could have effects that could alter tobacco
dependence later in life, and that the insult could alter
the trajectory of brain development.”
  While the study doesn’t establish whether the
differences in the insula can lead to smoking, or is the
[40] result of smoking, London says it highlights the role that
the brain region may play in how people respond to
nicotine and cigarettes. “I think this is very exciting
because it points to a vulnerability, a potential
vulnerability factor either to become nicotine dependent
[45] or for the effects of smoking to ultimately alter the

trajectory of brain development,” she says. That trajectory
could affect not only smoking behavior but
decision-making in general, since the insula is important
in such assessments.

PARK, Alice. Disponível em: <www.time.com//11386/teens-brainstructure-may-be-altered-by-smoking>. Acesso em: 13 maio 2015.

PET: Positron Emission Tomography.

MRI: Magnetic Resonance imaging.

“stroke” (l. 20): derrame.