I received this from another list I am on and thought Tipsters might find it
interesting.
Jeff Nagelbush
[EMAIL PROTECTED]
Ferris State University
>From: "Jeffrey Nagelbush" <[EMAIL PROTECTED]>
>To: [EMAIL PROTECTED]
>Subject: Fwd: [evol-psych] Evidence of brain chemistry abnormalities in
>bipolar disorder
>Date: Mon, 02 Oct 2000 16:06:34 EDT
>
>
>
>
>>From: "Ian Pitchford" <[EMAIL PROTECTED]>
>>Reply-To: "Ian Pitchford" <[EMAIL PROTECTED]>
>>To: <[EMAIL PROTECTED]>
>>Subject: [evol-psych] Evidence of brain chemistry abnormalities in bipolar
>>disorder
>>Date: Mon, 2 Oct 2000 09:47:50 +0100
>>
>>FOR RELEASE: 2 OCTOBER 2000 AT 00:01 ET US
>>University of Michigan Health System
>>http://www.med.umich.edu/1toolbar/whatsnew.htm
>>
>>U-M team finds evidence of brain chemistry abnormalities in bipolar
>>disorder
>>
>>30% higher concentration of certain signaling cells may help explain,
>>treat
>>"manic depression"
>>
>>ANN ARBOR, MI - People with bipolar disorder have an average of thirty
>>percent
>>more of an important class of signal-sending brain cells, according to new
>>evidence being published by University of Michigan researchers.
>>
>>The finding, in the American Journal of Psychiatry, solidifies the idea
>>that
>>the disorder has unavoidable biological and genetic roots, and may explain
>>why
>>it runs in families.
>>
>>The discovery is the first neurochemical difference to be found between
>>asymptomatic bipolar and non-bipolar people. It could help the
>>understanding
>>and treatment of a disease that affects as much as 1.5 percent of the
>>population. Bipolar disorder has in the past been known as manic
>>depression.
>>
>>"To put it simply, these patients' brains are wired differently, in a way
>>that
>>we might expect to predispose them to bouts of mania and depression," says
>>Jon-Kar Zubieta, M.D., Ph.D., assistant professor of psychiatry and
>>radiology
>>at the U-M Health System. "Now, we must expand and apply this knowledge to
>>give
>>them a treatment strategy based on solid science, not on the current
>>method of
>>trial and error. We should also work to find an exact genetic origin, and
>>to
>>relate those genetic origins to what is happening in the brain."
>>
>>Bipolar disorder is marked by wild, cyclical mood swings, which typically
>>begin
>>in a person's late teens or twenties and strike men and women with equal
>>frequency. Its milder, type II form causes depression alternating with
>>hyperactivity, while the more severe type I disorder produces frenzied,
>>even
>>psychotic episodes that may send the patient to the hospital, followed by
>>deep,
>>crippling depressions. Current treatment uses a mix of mood-stabilizing,
>>anti-psychotic and antidepressant drugs, but patients and physicians often
>>struggle to strike the right combination.
>>
>>Zubieta and his colleagues made the discovery in 16 patients with type I
>>bipolar disorder using a brain imaging technique called positron emission
>>tomography, or PET. The scans let them see the density of cells that
>>release
>>the brain chemicals dopamine, serotonin and norepinephrine.
>>
>>These monoamines, as the chemicals are called, send signals between brain
>>cells, or neurons. They're involved in mood regulation, stress responses,
>>pleasure, reward, and cognitive functions like concentration, attention,
>>and
>>executive functions. Scientists have hypothesized their role in bipolar
>>disorder for decades, but have never proven it.
>>
>>The new U-M result points to a clear difference in the density of
>>monoamine-releasing cells in the brains of bipolar people even when they
>>are
>>not having symptoms. Zeroing the PET scanner in on areas of the brain
>>where
>>monoamine-releasing cells are concentrated, the team looked for the faint
>>signal of a weakly radioactive tracer, DTBZ, which they had injected into
>>the
>>bloodstream of the 16 participants and 16 people without bipolar disorder.
>>
>>DTBZ binds only to a protein called VMAT2 inside monoamine-releasing
>>cells,
>>making it a good tracking device for the density of those cells. It is
>>also
>>often used in PET scanning to study Parkinson's disease, which is
>>characterized
>>by a severe shortage of cells that produce dopamine. On PET scans, DTBZ
>>density - and therefore monoamine cell density - can be quantified by the
>>amount of radioactive signal present in different areas.
>>
>>By looking at the intensity of the DTBZ signal in all the subjects'
>>brains, the
>>U-M team found that bipolar patients averaged 31 percent more binding
>>sites in
>>the region known as the thalamus, and 28 percent more in the ventral brain
>>stem. In the thalamus, bipolar women actually had levels nearing those of
>>healthy comparison subjects, but bipolar men had a 42 percent higher
>>binding
>>rate, suggesting that there may be specific biological causes for the
>>clinical
>>differences in the course of the illness in men and women.
>>
>>Adding in the results of functional tests, they found that the more
>>monoamine
>>cells patients had, the lower their scores on tests of executive function
>>and
>>verbal learning. This finding confirms earlier results from research at
>>the
>>U-M, and suggests that the altered brain chemistry due to the excess
>>monoamine
>>cells may directly impact the patients' cognitive and social function.
>>
>>The study was carefully designed to produce consistent results. It
>>compared
>>brain scans and neuropsychological test results from bipolar disorder I
>>patients who were using medications to control their symptoms, and healthy
>>subjects matched to the bipolar subjects for age, sex, ethnicity,
>>handedness
>>and other factors. Careful physical and psychiatric exams ruled out
>>differences
>>caused by other variables.
>>
>>Now, Zubieta and his colleagues hope their initial finding will lead to
>>further
>>research on brain chemistry and bipolar disorder. Specifically, more study
>>is
>>needed to examine which kinds of monoamine cells are involved - Zubieta
>>especially suspects those that produce serotonin and norepinephrine. Those
>>findings could help define specific subtypes of bipolar disorder, and aid
>>development of medications and drug combinations that target a specific
>>patient's personal brain chemistry to alleviate symptoms.
>>
>>Genetic research, too, will be needed to find out why bipolar brains grow
>>more
>>than the usual allotment of such cells. Bipolar disorder I has a strong
>>but
>>still unknown tie to DNA; studies of identical twins show that if one twin
>>has
>>it, the other has an 80 percent chance of having it, too. Zubieta is
>>hopeful
>>that genetic markers will one day be found that can help people know their
>>risk
>>of developing bipolar disorder.
>>
>>A combination of both genetic research and neuroimaging studies would help
>>define both the genetic components of this illness, and their relationship
>>with
>>the expression of specific brain chemical markers in specific patients.
>>
>>The U-M is launching a new trial that will enroll patients who have just
>>been
>>diagnosed with bipolar disorder, and those with a family history of the
>>disease
>>that puts them at higher risk.
>>
>>"The reality is that we still have only sketches of what is going on in
>>these
>>brains, what the basic changes are, and how they are related to the course
>>of
>>illness," Zubieta says. "We need to look farther."
>>
>>
>>
>>The study was funded by the U-M's General Clinical Research Center, by the
>>National Alliance for Research on Schizophrenia and Depression, and by the
>>Mental Illness Research Association's Arthur Forrest Tull II Research
>>Fund.
>>http://www.eurekalert.org/releases/umhs-utf092700.html
>>
>>
>>
>>
>>
>>To subscribe/unsubscribe/select DIGEST go to:
>>http://www.egroups.com/group/evolutionary-psychology
>>Cognition, Evolution, and Behavior by Sara J. Shettleworth
>>http://www.amazon.co.uk/exec/obidos/ASIN/019511048X/humannaturecom/
>>Evolutionary Psychology Archive: 7000+ Items
>>http://www.egroups.com/messages/evolutionary-psychology
>>
>
_________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.
Share information about yourself, create your own public profile at
http://profiles.msn.com.
