[psychiatry-research] Discovery of brain phenomenon could lead to better drugs for certain mental illnesses
- FOR RELEASE: 27 MARCH 2000 AT 05:00 ET US
Johns Hopkins Medical Institutions
Discovery of brain phenomenon could lead to better drugs for certain mental
Researchers at Johns Hopkins have discovered a phenomenon in the brains of
individuals with schizophrenia and other mental illnesses that may help
doctors develop better drugs.
According to the results of the study that appear in the March issue of
Molecular Psychiatry, individuals with schizophrenia, bipolar disorder and
major depression have lower than average levels of a certain brain protein
and, thus, less "plastic" brains. By examining the cascade of events that
lead to the formation of the protein, the researchers hope to improve current
therapeutics. The discovery also supports a theory that retroviruses may be
associated with some cases of mental illness.
"When designing treatments for these disorders, it is probably going to turn
out to be very important to interfere with the cascade of interactions," says
Nancy Johnston-Wilson, Ph.D., a research associate at the Stanley
Neurovirology Laboratory at Hopkins and lead author of the study.
In an effort to more precisely identify the cascades associated with these
disorders, Johnston-Wilson examined levels of some key proteins in autopsied
brains from 24 schizophrenics, 23 individuals with bipolar disorder, 19
people with major depression and 23 individuals unaffected by the diseases.
The researchers discovered that the brains of those with the three mental
illnesses had significantly lower levels of phosphorylated glial fibrillary
acidic protein (GFAP) in comparison to the controls. GFAP usually forms
filaments and is part of the structural network of cells that nourishes and
detoxifies nerve cells. When GFAP becomes phosphorylated, however, these
filaments fall apart, making membranes flexible and allowing for cell
division. The researchers, therefore, conclude that individuals with these
three mental illnesses have brains that are less plastic than the brains of
individuals without the disorders. Plasticity is a normal aspect of the brain
that allows it to adjust to inputs.
Next, the researchers plan to examine the series of biochemical events
responsible for phosphorylating GFAP. Many biochemicals including
neurotransmitters, growth factors and cytokines (proteins that regulate the
intensity and duration of inflammatory response) can trigger phosphorylation.
"Identification of pathways which are altered in disease will give us a
logical place to target for therapeutic interventions," says Johnston-Wilson.
"Since the drugs currently used to treat schizophrenics take a couple of
weeks to take effect, it's likely they are targeting the same pathways but in
a more round about way. If we knew, more directly, what was altered, we could
design better therapies."
The decrease in phosphorylated GFAP also supports a new theory that some
mental illnesses are triggered by a virus, because cell cultures of viruses
including HIV-1 also show a decrease in the protein. "If mental illness is
due to viral involvement, we may be seeing the same thing," says
To learn more about viruses and their role in mental illness, travel to
http://www.med.jhu.edu/stanleylab/. Other authors of the study include Robert
Yolken from the Stanley Neurovirology Lab at Johns Hopkins School of
Medicine; Andrew Shore from the Health Services Research and Development
Center at Johns Hopkins School of Hygiene and Public Health; E. Fuller Torrey
from the Stanley Foundation Research Programs, NAMI Research Institute in
Bethesda, Md; and Christina D. Sims, Jean-Paul Hofmann and Leigh Anderson
from Large Scale Biology Corporation in Rockville, Md.