STAY AWAY FROM METH, PREGNANT WOMEN WARNED

Fetal Brains Less Equipped To Repair Molecular Damagethan Adult
Brains: Researcher

Smoking, drinking and some prescription drugs have long been no-nos
for pregnant women.

Although the effects of illicit drugs are harder to study, one
University of Toronto researcher has found pregnant mice who receive
just one low dose of methamphetamine have babies with developmental
problems and compromised motor skills.

"It's very difficult to know the (troubles) that meth causes in humans
because there's very little documentation about what they're exposed
to," says Peter Wells, a U of T toxicology professor. "You will see
reports of children with a range of behavioural problems -- from motor
co-ordination to cognition, to behaviour (and) attention deficit syndrome."

Wells will talk about his research tonight in Saskatoon as the
kick-off to Brain Awareness Week, which is put on by the Saskatchewan
Neuroscience Network from the University of Saskatchewan.

For years, Wells' lab has studied chemicals that cause oxidative
stress, and consequently damage, to the brain.

Researchers believe methamphetamine use results in the release of free
radicals in the brain, highly active molecules that set off a chain of
destructive reactions to biological molecules, including DNA.

While adult brains have many enzymes to help counter free radical
reactions and repair the damage they cause, Wells said fetal brains
have less than five per cent of that helpful enzyme activity compared
to their mothers.

Methamphetamine use was popular in the 1970s, and has regained
popularity in the past decade with the resurgence of ecstasy and
crystal meth, Wells said.

"It again has become, in some parts of society, in epidemic use among
pregnant women," he said. "Many times, they don't think it has any
effect. The question is, does it, and what's the mechanism?"

After injecting pregnant mice with the drug, Wells' team later put the
babies on a slowly rotating rod to test their motor skills. Mice can
usually stay on the rod without difficulty, Wells said, but the mice
exposed to meth in the womb were more likely to lose their footing and
fall off.

It was a long-term effect, because by six months of age, the meth mice
were still tumbling off the rod.

"(In a mouse lifespan), that's like into their 30s or so, and they're
still not showing any signs of recovery," Wells said, adding the
results suggest damage is likely permanent.

The results were published in 2005 in the journal Free Radical Biology
and Medicine.

Wells cautions there's no guarantee the results translate to
humans.

Studying human subjects would be tough, he said. If drug users were to
participate, there's no way to know exactly what dose the woman took,
whether it was laced with another drug, or whether the woman uses any
other drugs -- illegal, legal or herbal remedies, he said.

"It's much harder to do that kind of study and get reliable
information about what's going on," he said. Researchers are gathering
data, but it will take time to get meaningful results.

By exposing some growing baby mice to methamphetamine when they were
embryos, and others when they were a fetus, the results underline that
there is no safe time for the use of illicit drugs during pregnancy,
Wells said.

Although the first trimester is a delicate time when chemicals like
thalidomide can cause structural defects, intelligence and cognitive
abilities, motor function and ability to focus all develop in the
third trimester, Wells said.

"We still don't know a lot about what affects the developing fetus,"
he said. "When in doubt, don't take anything."

Wells' group also found methamphetamine damaged fetal brains
differently than adult brains.

In adults, the drug causes the degeneration and disappearance of nerve
terminals. That didn't happen to the babies in the womb.

"We were quite surprised," Wells said. "Something else is going on in
the fetus. Something's not being formed properly, and we don't know
what it is."

Wells' talk, 7 p.m. tonight at the Hilton Garden Inn, has free
admission.

Brain Awareness Week also features three free lectures at the Francis
Morrison Library on Tuesday, Wednesday and Thursday at 6:30 p.m., a
"brain walk" exhibit on Sunday at City Hospital and a high school
science fair with brain-related projects.