Good reasons to smile at dedication of new PET
camera, University of Pennsylvania, Philadelphia,
April 4, 2002.
Prominent neuroscientists Dr. Anna Rose Childress
and Dr. Charles O'Brien, now have the specialized
brain scanner they need to develop medications to
control craving in cocaine addicts. This new PET
camera developed by Dr. Joel Karp's UPENN design
team has a highly innovative array of 18500 detectors
that can localize human brain activity to within
3.5 millimeters. With the accuracy available from
the new PET camera, Dr. Childress can determine
exactly where in the brain a therapeutic medicine
is having its effect. Developing medications to
alleviate the harmful effects of drugs of abuse
is a top priority for White House Drug Czar John
Walters and is supported by the National Institute
on Drug Abuse (NIDA). CTAC Director Dr. Al Brandenstein runs
Walters' program providing technologically innovative,
state-of-the-art brain scanners to major US
research institutions specifically to work on drugs
of abuse.
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| Dr. Volkow with brain images of long-term meth users, Brookhaven National Laboratory, Long Island, NY |
One of the first CTAC-provided brain cameras went
to a team of medical scientists led by Dr. Nora
Volkow at Brookhaven National Laboratory in
Upton, New York. They have used the machine to
examine the brains of former methamphetamine
addicts. The recovering drug abusers had been off
meth for as long as 11 months and may have
believed that their bodies and brains had escaped
lasting injury, but what Dr. Volkow and her team
discovered is chilling. Reported in the American
Journal of Psychiatry, their study, funded by NIDA,
says the brains of long term meth users appear
permanently changed, leaving the recovering
addicts with impaired memory and reduced physical
coordination. Dr. Volkow told us her team was
surprised to see from the PET camera images, that
the subjects' brains showed the same kind of
swelling normally associated with physical trauma,
like the effect of radiation used to treat a tumor.
Mapping CTAC's plan
to arm American brain
researchers with
state-of-the-art
technology to
develop counterdrug
medications and
new knowledge
leading to better
prevention
and treatment
|
|
Edward, (photo right), a paraplegic and a
cocaine addict, reported to Dr. Childress that
Baclofen, the drug he takes to control muscle
spasms, also lets him control his cocaine craving.
Dr. Childress is pursuing that lead vigorously
and her work with Edward was featured on
the recent PBS series on the human brain.
Dr. Childress' new, CTAC-sponsored PET camera
was specifically designed to facilitate her NIDA-funded
craving studies.
World's Most Powerful Brain Scanner
for Use in Human Beings Provided
by CTAC to Massachusetts General
Hospital is on Historic Mission
Principal Investigator Prof. Hans Breiter, MD, (inside machine during its installation), plans to
use the giant 7-Tesla fMRI to undertake a project
of epic proportions, "Mapping the Circuitry
of Human Motivation and Reward." Dr. Breiter
hopes to get answers to questions about treatment
and prevention that require unprecedented
access to the innermost workings of the
human brain. Until this machine was created
(under the guidance of MGH's Dr. Bruce Rosen),
such access was theoretical, only.
[ Medical Research ]
"Amped up! Angry! Misunderstanding people! Them misunderstanding me!"
That is how this young methamphetamine addict
described some of the changes in her brain that
she believes the drug has induced. What she did
not know was while she was taking the drug in
the streets, researchers at Brookhaven National
Laboratory led by Dr. Nora Volkow were making
an important and chilling discovery. Working with
Dr. Linda Chang and using a CTAC sponsored PET
camera, Dr. Volkow documented long-term brain
damage in methamphetamine users and
suggested that this drug-induced brain damage
may lead to early onset of the symptoms of
Parkinson's disease.
Dr. Volkow's discoveries with the PET camera
include the observation that differences in individuals'
natural brain chemistry may lead to addiction
in some people who try drugs once, while sparing
others the horrors of being addicted. She used her
PET scanner at Brookhaven to test the brain
response of 23 healthy young men to the legal
stimulant, Ritalin. About half of those men had
lower D2 dopamine receptors in their brains. They
were the same subjects who said the Ritalin experience
was pleasurable, suggesting, said Dr. Volkow that,
"people with fewer dopamine receptors may take
drugs to activate pleasure circuits in
the brain which could be one of the factors that
predisposes a person to drug abuse. "
The CTAC sponsored Primate Micro PET brain
scanner was built by Dr. Simon Cherry to meet the
research requirements of UCLA Prof. Edythe
London, a pioneer in the neuroscience
of addiction.
She will use the brain scanner, "to explore gene
expression in monkey brain regions crucial to
the reward effects of cocaine and other drugs. For the first time, the links between drug abuse and brain function will be linked to the expression of certain genes that can then be monitored externally. The implications for the development of counterdrug medications could be
very significant."
