Several times in the course of his frantic
and stressful day, LSA sophomore Joe Zhou takes a breather from the
world by lighting up a cigarette.

“I smoke because it helps me relax,” exhales
Zhou.

Smoking a cigarette may give people a temporary reprieve from
the stresses of everyday life, but recent findings from University
neuroscientists show that smoking may have more permanent effects
on the brain.

At this year’s Society for Neuroscience meeting held in
San Diego, a team from the University presented research that found
smoking has lasting effects on the brain’s “feel
good” chemical system. This system contains chemicals called
endogenous opioids, which are the same ones activated by heroin and
morphine.

Using radioactive scanning technology that tracks activity in
areas of the brain, researchers from the departments of psychiatry,
pharmacology and the University Addiction Research Center found
increased concentrations of “feel good chemicals” in
smokers’ brains.

“Smokers have an altered opioid flow all the time when
compared with non-smokers,” said David Scott, a graduate
student in the neuroscience program who presented the results at
the convention last month. “Smoking a cigarette further
alters that flow by 20 to 30 percent in regions of the brain
important to emotions and craving.”

During smoking, participants reported feeling “more
relaxed, and less alert and nervous,” according to the study.
The sources for these feelings were pinned down to specific areas
in the brain using Positron Emission Tomography Scanning.

Scientists tagged a chemical by making it radioactive and then
traced its path through the brain as it was used up. The areas of
the brain that were more active during smoking consumed more of the
chemical, and lit up under the PET scanner.

Smoking helped downplay reported feelings of stress and
increased relaxation, said Ed Domino, pharmacology emeritus
professor and one of the principal investigators behind the
research. “Certain areas in smokers’ brains turned up
and certain areas turned down.”

But regular smokers showed consistently stronger responses,
demonstrating greater ability to handle stress and create feelings
of well-being. However, the authors of the study emphasized that
these benefits were greatly outweighed by the risks of smoking.
“Smoking is a terrible thing,” Domino said.

In addition, some of the cigarettes used in the study were
de-nicotinized and had to be specially obtained from the Philip
Morris Research Center. Surprisingly, smokers couldn’t tell
the difference between normal cigarettes and those with the highly
addictive nicotine removed. The opioid levels in the
subjects’ brains increased for both types of cigarettes,
suggesting the large role played by psychological addiction.

Domino acknowledged the irony of accepting research support from
a cigarette manufacturer.

“I have a love-hate relationship with the company. But
they should cough up the dollars and support research, ” said
Domino.

Under terms ironed out in a series of settlements between the
tobacco industry and state attorneys general in 1998, Philip Morris
committed itself to funding smoking research.

On the industry’s commitment to anti-tobacco research,
Domino only said the test cigarettes “all tasted pretty
lousy,” and hoped to use the subjects’ own preferred
brands in the next study.

The preliminary experiment enlisted six pack-a-day smokers who
were paid about $100 an hour to light up.

However, Domino was quick to emphasize that the participants
“had to work for it.” The subjects weren’t
allowed to smoke for 12 hours prior to the study, with carbon
monoxide breath-detectors and nicotine blood-detectors catching any
cheaters. By the morning of the trials, the subjects were
“really anxious, really craving a cigarette,” Domino
said.

They were then placed in a PET scanner lying on their backs with
their heads restrained for three hours, while smoking under
controlled conditions. The equipment had to be specially modified
to allow smoking while scanning.

Taking place inside the University hospital, Domino said the
cigarette smoke had to be handled like “poison gas,”
with the smokers using fans and modified gas masks to catch their
exhalations. The noxious smoke was sent directly into the
hospital’s central vacuum system, mixing with the rest of the
hospital’s waste gases and finally “blown out from the
roof into the skies of Ann Arbor.”