Disorder, Schizophrenia Key Found
by Daniel DeNoon, WebMD Medical News, October 28, 2004
For more articles like this
stress-activated molecule underlies many of the symptoms of some
mental illnesses, a new study shows.
We control our behaviors, thoughts, and emotions via an
important part of the brain: the prefrontal cortex. People with
injuries to this part of the brain become impulsive,
distractible, and have poor judgment. Major damage to the
prefrontal cortex can cause thought disorders and
These symptoms are also seen in people with bipolar disorder and
with schizophrenia. These mental illnesses worsen with stress.
Recent studies also link worsening bipolar disorder and
schizophrenia with changes in brain signaling by a molecule
called protein kinase C or PKC.
In rat and monkey studies, Yale researcher Amy Arnsten, PhD, and
colleagues delivered PKC directly to the prefrontal cortex of
rats and monkeys. Sure enough, PKC impaired the animals' mental
Drugs that block PKC restored mental functioning. Some of these
drugs include medicines commonly used to treat mental illness,
such as lithium and valproate.
Arnsten and colleagues report their findings in the Oct. 29
issue of Science.
"Excessive PKC activation can disrupt ... regulation of behavior
and thought, possibly contributing to signs of prefrontal
cortical dysfunction such as distractibility, impaired judgment,
impulsivity, and thought disorder," Arnsten and colleagues
It's possible that new drugs with improved PKC-blocking activity
could lead to better treatment of bipolar disorder,
schizophrenia, and perhaps other mental illnesses.
Interestingly, PKC plays a role in lead poisoning. The findings,
Arnsten says, could lead to a better understanding of the
symptoms of distractibility and impulsivity seen in children
with lead poisoning.
back to the top ~
back to Breaking News
~ back to