FOR IMMEDIATE RELEASE
August 11, 2008
Contact: Christine Guilfoy
Office: (301) 634-7253
cguilfoy@the-aps.org
Researchers Block Damage to
Fetal Brain Following Maternal Alcohol Consumption
Study with sheep holds promise for humans, but more research needed
BETHESDA, Md. (August 11, 2008) − In a study on fetal
alcohol syndrome, researchers were able to prevent the damage that alcohol
causes to cells in a key area of the fetal brain by blocking acid sensitive
potassium channels and preventing the acidic environment that alcohol
produces. The cerebellum, the portion of the brain that is responsible for
balance and muscle coordination, is particularly vulnerable to injury from
alcohol during development.
The researchers also found that although alcohol lowers
the amount of oxygen in the blood of the mother, it is not the lack of
oxygen that damages the fetal cerebellum, but the drop in pH.
The study with sheep, published in the August issue of
the American Journal of Physiology, demonstrated that the damage can
be prevented by blocking acid sensitive potassium channels, known as TASK
channels, that lead into the Purkinje cells. The study, “Acid Sensitive
Channel Inhibition Prevents Fetal Alcohol Spectrum Disorders Cerebellar
Purkinje Cell Loss,” was carried out by Jayanth Ramadoss, Emilie R. Lunde,
Nengtai Ouyang, Wei-Jung A. Chen and Timothy A. Cudd. The research was done
at Texas A&M University.
Fetal Alcohol Syndrome
Fetal alcohol syndrome is a condition in which maternal
drinking during pregnancy injures the brain of the developing fetus. Alcohol
is the most common cause of injury to the fetal brain. Children born with
fetal alcohol syndrome may have cognitive impairments and difficulty
regulating their behavior. They often have difficulty in school and exhibit
behavioral problems, such as impulsiveness, later in life.
The syndrome is estimated to occur in approximately one
in every 1,000 births in Western countries. Milder forms of the condition,
known as fetal alcohol spectrum disorders, occur more frequently.
Maternal drinking lowers the blood pH of both the
mother and the fetus, making the blood more acidic. The researchers
hypothesized that this acidity damages the Purkinje cells of the fetal
cerebellum. Using 56 pregnant sheep, they induced the change in pH in some
sheep using alcohol, while in others they manipulated the extracellular pH.
This approach allowed them to test their hypothesis that it was the fall in
pH that created the damage, not the alcohol, per se.
Alcohol produced a 45% reduction in Purkinje cells of
the fetal cerebellum, while the pH changes alone produced a 24% decrease. A
drop in the number of Purkinje cells in the cerebellum is a measure of
damage.
However, when the researchers used a drug, doxapram, to
block the TASK channels leading into the Purkinje cells, they prevented the
change in pH in the fetal cerebellar cells and prevented any reduction in
the number of these cells.
“This study demonstrates that direct pharmacological
blockade of TASK 1 and TASK 3 channels protects the most sensitive target of
fetal alcohol exposure, cerebellar Purkinje cells,” the authors concluded.
Finding adds to growing
body of work
This study complements work by other researchers who
have found success with supplements such as choline, a precursor for the
neurotransmitter acetylcholine. These supplements may work on the same
mechanism that Dr. Cudd’s lab has been researching.
Editor’s Notes: To arrange an interview with Dr.
Cudd, please contact Christine Guilfoy at
cguilfoy@the-aps.org or (301) 634-7253.
A fuller audio interview with Drs. Cudd and Ramadoss is
available in Episode 12 of the APS podcast, Life Lines, at
www.lifelines.tv.
Funding: The research was funded by the National
Institutes of Health (NIH) Pediatrics Initiatives and the NIH National
Institute on Alcohol Abuse and Alcoholism.
Physiology
is the study of how molecules, cells, tissues and organs function to create
health or disease. The American Physiological Society (APS) has been an
integral part of this scientific discovery process since it was established
in 1887.
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