By Bimal Rajkomar
Daily Bruin Reporter
Funded by smokers themselves, researchers have found that
nicotine degenerates the part of the brain that controls sexual
arousal, emotional control and REM sleep.
Nicotine causes degeneration in one part of the brain, according
to professor of psychology Gaylord Ellison, who announced the
finding in the journal Neuropharmacology, and at this year’s
meeting of the Society for Neuroscience.
Ellison found that nicotine causes selective degeneration of the
fasciculus retroflexus, the part of the higher brain that primarily
controls the dopamine and serotonin levels in the body.
Dopamine controls movement, emotional response, and the ability
to experience pleasure and pain, while serotonin regulates a
person’s mood.
In past research, Ellison’s team has shown that drugs such
as amphetamines, cocaine and ecstasy damage one half of the
fasciculus retroflexus, but new research shows that nicotine
affects the other half.
“We know nicotine is a toxic substance, but the fact that
it kills this one neurotract is striking,” said Ellison.
The selective damage to the tract may hold implications for
addiction.
“It seems likely that fasciculus retroflexus is linked to
drug addiction and relapse,” Ellison said in a statement.
“In chronic smokers, this tract may well play a major role in
the addiction to nicotine.”
The study stemmed from previous research but it was primarily
the result of chance. About two and a half years ago, the
researchers were studying the effects of other drugs on rat
brains.
The sample sheets, which are sent to the lab for analysis, have
16 slots for brain tissue. The researchers only had experimental
tissues for 15 slots. With the extra slot, they just happened to
submit a sample of the brain of a rat on nicotine to the lab.
When the results came back, they were so striking that it
started this most recent study.
Although the study shows the negative effects of nicotine,
Ellison suggested that it has some positive effects on the
body.
“Its easy to make a story about brain degeneration and
that cigarettes are bad, but there is a whole other story,”
Ellison said. “Nicotine has other beneficial
effects.”
He noted that rats on nicotine perform better on some cognitive
tests, and that human smokers have lower incidences of
Parkinson’s and Alzheimer’s disease.
“The goal is to get the benefits of nicotine without the
damage,” said Ellison, who recently submitted a grant
proposal to Philip Morris.
He anticipates that his current research will bring on more
studies of the fasciculus retroflexus, a part of the brain he
considers to be understudied.
“We want to find what exactly is causing the degeneration
and what neurotoxic mechanisms are involved,” Ellison
said.
The researchers performed a minor procedure on the rats,
inserting a pump to the back of rats which delivered a constant
flow of nicotine.
Because of the methods used in the study, fourth-year psychology
graduate student Janice Carlson who worked on the study, said that
people should exercise caution before making connections with
humans.
“The rats were exposed to a constant dosage of nicotine,
while smokers go through peaks and valleys of nicotine
levels,” she said.
Also, the rats were given a constant dosage, while smokers
usually start out with low dosages and increase with time.
With every tobacco product they buy, smokers are actually paying
for research to find out how bad their habit is for their
bodies.
The passage of Proposition 99 in 1988 raised taxes on cigarettes
by 25 cents ““ an increase still in place today.
Among other programs, Proposition 99 included legislation to
establish a medical research program, the UC-led Tobacco-Related
Disease Research Program.
“It was a natural choice.” said director of the
Tobacco Related Disease Research Program Susanne Hildebrand-Zanki.
“It was the most neutral, and the expertise was already
there.”
The program has been active since 1989, with a budget of about
$20 million, but that funding is bittersweet.
“I would love to be out of business,”
Hildebrand-Zanki said.
“Realistically, I don’t see that it will disappear
soon,” said Hildebrand-Zanki who anticipates the program to
go on for about 10 more years.