Tuesday, February 10, 2004

[left brain stuff:]
News Clips from NIMH

Contact: Jules Asher
NIMH Press Office

Scans have pinpointed circuits in the monkey brain that could be precursors of those in humans for speech and language. As in humans, an area specialized for processing species-specific vocalizations is on the left side of the brain, report Drs. Amy Poremba, Mortimer Mishkin, and colleagues at the National Institute of Mental Health (NIMH), Warren G. Magnuson Clinical Center (CC), components of the National Institutes of Health (NIH), and the University of Iowa. An area near the left temple responded significantly more than the same area on the right only to monkey calls, not to other animal calls, human voices or various other sounds. The researchers published their findings in the January 29, 2004 Nature. [...]

To find out how this works, the researchers used PET (positron emission tomography) scanning. A radioactive tracer visualized the parts of the brain that were active while different types of sounds were being processed. After eight healthy monkeys heard a series of monkey calls, an area just below the left temple, at the front of the left temporal lobe (left dorsal temporal pole), activated significantly more than its mate on the right. Yet, this area failed to similarly activate when the animals heard a variety of other sounds – bells, tones, dog barks, bird tweets, a human voice, scrambled monkey calls, etc. Instead, significant activation was seen in a different temporal lobe area on the right side of the brain, which seems to process virtually every sound. [...]

December 22, 2003 

Research on the genetics of mental illness, most of it NIMH-funded and much of it in the Institute’s own laboratories, was named the #2 scientific “breakthrough of the year” by Science magazine in its December l9, 2003 issue. The prestigious journal selected the mental health studies first of nine runners-up – second only to newfound insights into the nature of the cosmos.  It cited progress not only in identifying genes that increase one’s risk of developing schizophrenia, depression and bipolar disorder, but also in “unraveling” how the genes work in the brain to influence vulnerability.

Among studies specifically mentioned is the finding by NIMH grantees Drs. Avshalom Caspi and Terrie Moffitt, University of Wisconsin, that a variant of the serotonin transporter gene doubles the risk of depression following life stresses in early adulthood.  Also, NIMH’s Drs. Ahmad Hariri’s and Daniel Weinberger’s finding that the same gene variant biases the amygdala’s response toward increased anxiety when viewing frightening faces. 

Also cited are discoveries by NIMH’s Drs. Michael Egan, Venkata Mattay, Mayada Akil and Weinberger about how a particular version of the COMT gene slightly increases risk of schizophrenia by impairing prefrontal function.

Work by Egan and colleagues is also credited for showing how the BDNF gene , which has been linked to bipolar disorder, affects memory in humans through effects on the hippocampus.

 August 07, 2003

Blocking the formation of neurons in the hippocampus blocks the behavioral effects of antidepressants in mice, say researchers funded by the National Institutes of Health (NIH). Their finding lends new credence to the proposed role of such neurogenesis in lifting mood. It also helps to explain why antidepressants typically take a few weeks to work, note Rene Hen, Ph.D., Columbia University, and colleagues, who report on their study in the August 8th Science.

“If antidepressants work by stimulating the production of new neurons, there’s a built-in delay,” explained Hen, a grantee of NIH’s National Institute of Mental Health (NIMH) and National Institute on Drug Abuse (NIDA). “Stem cells must divide, differentiate, migrate and establish connections with post-synaptic targets – a process that takes a few weeks.”

“This is an important new insight into how antidepressants work,” added NIMH director Thomas Insel, M.D. “We have known that antidepressants influence the birth of neurons in the hippocampus. Now it appears that this effect may be important for the clinical response.”

[right brain stuff:] 

Obviously, the pace of neuroscience research is picking up.  The development of techniques in cell biology, neuroimaging, and genetics have opened up entirely new areas of study.  What was once considered a classic, major problem in philosophy, the Mind-Body Problem, is becoming a non-issue.  What is particularly exciting is the empirical validation of longstanding beliefs in the mental health field: there is a genetic substrate that influences, but does not strictly determine, the development of mental illness; that the brain is capable of structural change and of physically healing itself; and that there is neurochemical rationale for the action of psychiatric medication that is not simply a matter of sedation or numbing of emotional experience. 

From time to time, persons will speculate that antidepressants are not truly therapeutic; all they do is cover up feelings.  There is an increasing mass of evidence to the contrary, such as the August 7, 2003 article on neurogenesis.  Persons who complain that mental health is not scientific should notice that mental health genetics was named the #2 scientific breakthrough of 2003.  The article on Monkey Talk illustrates that there is a physiological reaction to noises that are identified as communication, as distinct from arbitrary noises.  This indicates that the brain is not a passive processor of sensory input.  Sensation are sorted according to meaning, and processed accordingly.  The only way that meaning can be discerned is via an emotional association to the signal.  Thus, we have evidence that "mind" and "body" are different aspects of the same thing; there is no dichotomy.
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