What do suffering a traumatic brain injury and using club drugs have in common? University of Florida researchers say both may trigger a similar chemical chain reaction in the brain, leading to cell death, memory loss and potentially
irreversible brain damage.
A series of studies at UF over the past five years has shown using the
popular club drug Ecstasy, also called MDMA, and other forms of
methamphetamine lead to the same type of brain changes, cell loss and
protein fluctuations in the brain that occur after a person endures a
sharp blow to the head, according to recent findings.
“Using methamphetamine is like inflicting a traumatic brain injury on
yourself,” said Firas Kobeissy, a postdoctoral associate in the College
of Medicine department of psychiatry. “We found that a lot of brain
cells are being injured by these drugs. That’s alarming to society now.
People don’t seem to take club drugs as seriously as drugs such as
heroin or cocaine.”
Working with UF researchers Dr. Mark Gold, chief of the division of
addiction medicine at UF’s McKnight Brain Institute and one of the
country’s leading experts on addiction medicine, and Kevin Wang,
director of the UF Center for Neuroproteomics and Biomarkers Research,
Kobeissy compared what happened in the brains of rats given large doses
of methamphetamine with what happened to those that had suffered a
traumatic brain injury.
The group’s research has already shown how traumatic brain injury
affects brain cells in rats. They found similar damage in the rats
exposed to methamphetamine. In the brain, club drugs set off a chain of
events that injures brain cells. The drugs seem to damage certain
proteins in the brain, which causes protein levels to fluctuate. When
proteins are damaged, brain cells could die. In addition, as some
proteins change under the influence of methamphetamine, they also begin
to cause inflammation in the brain, which can be deadly, Kobeissy said.
Kobeissy and other researchers in Gold’s lab are using novel protein
analysis methods to understand how drug abuse alters the brain. Looking
specifically at proteins in the rat cortex, UF researchers discovered
that about 12 percent of the proteins in this region of the brain showed
the same kinds of changes after either methamphetamine use or traumatic
brain injury. There are about 30,000 proteins in the brain so such a
significant parallel indicates that a similar mechanism is at work after
both traumatic brain injury and methamphetamine abuse, Kobeissy said.
“Sometimes people go to the clubs and take three tablets of Ecstasy or
speed,” Kobeissy said. “That may be a toxic dose for them. Toxic effects
can be seen for methamphetamine, Ecstasy and traumatic injury in
different areas of the brain.”
About 1.3 million people over the age of 12 reported using
methamphetamine in the previous month, according to the 2006 National
Survey on Drug Use and Health. In 2004, more than 12 million Americans
reported having tried the drug, the survey’s findings show.
People often think the effects of drugs of abuse wear off in the body
the same way common medications do, but that may not be the case, Gold
said.
“These data and the previous four years of data suggest some drugs,
especially methamphetamine, cause changes that are not readily
reversible,” Gold said. “Future research is necessary for us to
determine when or if methamphetamine-related brain changes reverse
themselves.”
Gold and Dennis Steindler, director of UF’s McKnight Brain Institute and
an expert on stem cells, are planning studies to find out if stem cells
can be applied to repair drug-related brain damage.
UF researchers are also trying to uncover all the various ways drugs
damage and kill brain cells. During their protein analysis, researchers
discovered that oxidation was damaging some proteins, throwing the
molecules chemically off balance.
“When proteins are oxidized they are not functional,” Kobeissy said.
“When proteins are not working, the cell cannot function.”
Neurologist Dr. Jean Lud Cadet, chief of the molecular neuropsychiatry
branch of the National Institute on Drug Abuse, said analyzing proteins
is important to understanding how drugs such as methamphetamine affect
the brain.
“I think saying the results of methamphetamine abuse are comparable to
the results of a traumatic brain injury is a new idea,” Cadet said. “I
agree with (the findings). Our own work shows that methamphetamine is
pretty toxic to the brains of animals. In humans, imaging studies of
patients who use methamphetamine chronically show abnormalities in the
brain.
“Abuse of methamphetamine is very dangerous.”
This research was presented at a Society for Neuroscience conference
held recently in San Diego.
Source: Science Daily (Nov. 29, 2007)