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--- judith richards <[log in to unmask]> wrote:
> Symptoms of aging tied to brain chemistry
> By Penny Stern, MD
>
> NEW YORK, Jan 07, 2000 (Reuters Health) -- Some of the
> changes
> associated with aging appear to be due to the loss of a
> particular type
> of chemical receptor in the brain, scientists report in
> this month's
> issue of The American Journal of Psychiatry.
>
> Dr. Nora D. Volkow, based at the Brookhaven National
> Laboratory in
> Upton, New York, headed the team of researchers. ''This
> study
> investigated the effects of aging on dopamine, which is a
> chemical in
> the brain that modulates the communications between areas
> in the brain
> that are involved with movement, cognition, motivation,
> and reward,''
> she told Reuters Health. Cognition can be defined as
> memory and learning
> ability.
>
> Volkow and her team recruited 37 healthy individuals of
> varying ages to
> participate in the study. Using an imaging technique
> called positron
> emission tomography (PET) scanning to visualize the
> brain, the
> investigators ``measured both the levels of (dopamine D2)
> receptors as
> well as regional brain glucose metabolism, which serves
> as an index of
> brain function,'' she explained.
>
> After analysis of the data, the researchers found that
> aging correlated
> with a loss of dopamine receptors ``and that these losses
> were
> associated with a decline in activity in the frontal
> regions of the
> brain,'' Volkow said. The researchers ``interpret these
> results as an
> indication that the age-related losses in brain dopamine
> activity result
> in dysfunction of brain regions that are known to be
> involved with
> cognition, attention, and mood,'' she added.
>
> The significance of these findings is clear to Volkow.
> ''They suggest
> that the decline in cognitive abilities and the higher
> propensity for
> depression in the elderly may in part be due to the
> losses of brain
> dopamine receptors,'' she said, adding that treatment
> aimed at
> preventing the loss of dopamine receptors may help
> prevent some of the
> memory and mood changes that occur with aging.
>
> Based on these findings, two possible avenues of
> intervention could
> potentially limit dopamine receptor losses: drugs and
> life style
> changes, according to Volkow. Certain medications ``could
> help
> prevent... degeneration (of the dopamine systems),'' she
> noted. And,
> life style changes ``that include physical exercise,
> exposure to novel
> stimuli, exposure to experiences that motivate the
> individual, learning
> new skills, appropriate diet, (and) social interactions''
> may keep the
> dopamine systems intact, she continued.
>
> Commenting that a lack of stimulation may impair how well
> brain cells
> communicate with each other, Volkow explained that
> ''passive life styles
> with very fixed routines... that are not motivating may
> facilitate
> degenerative changes in the brain that occur with
> aging.''
>
> In fact, Volkow told Reuters Health, her team's next
> research step will
> be ``to understand how variables related to life style --
> such as
> exercise, diet, and sleep -- affect the loss of dopamine
> receptors as
> they occur with age.''
>
> SOURCE: The American Journal of Psychiatry January 2000.
> Copyright © 1996-2000 Reuters Limited.
>
> ~~~~
> Judith Richards, London, Ontario, Canada
> [log in to unmask]
>                           ^^^^
>                            \ /
>                          \  |  /   Today’s Research
>                          \\ | //         ...Tomorrow’s
> Cure
>                           \ | /
>                            \|/
>                           `````
>

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