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>Reply-To: "Ian Pitchford" <Ian.Pitchford@scientist.com>
>From: "Ian Pitchford" <Ian.Pitchford@scientist.com>
>Date: Wed, 1 Sep 1999 16:40:34 +0100
>X-Mailer: Microsoft Outlook Express 5.00.2314.1300
>Subject: [evol-psych] Scientists genetically engineer smarter mice,
>pointing way to smarter humans
>Scientists genetically engineer smarter mice, pointing way to smarter humans
>JEFF BARNARD, Associated Press Writer
>Wednesday, September 1, 1999
>Breaking News Sections
>(09-01) 04:56 PDT Scientists have genetically engineered brainy mice nicknamed
>``Doogie,'' pointing the way for research that could lead to human babies with
>higher IQs as well as drugs to treat Alzheimer's disease and stroke.
>Inserting an extra gene, researchers produced a strain of mice that
>a range of tasks, like recognizing a Lego piece they'd encountered before,
>learning the location of a hidden underwater platform and recognizing cues
>they were about to receive a mild shock.
>The improved learning and memory came from increased production of a brain
>protein called NR2B. The mice carried the enhanced abilities into adulthood,
>when learning ability and memory naturally taper off, and passed their
>heightened learning abilities on to their offspring.
>``This points to the possibility that enhancement of learning and memory or
>even IQ is feasible through genetic means, through genetic engineering,'' said
>Joe Z. Tsien, the assistant professor of molecular biology at Princeton
>University who led the research team.
>The findings, published in the Thursday issue of Nature, indicate a common
>mechanism lies at the root of all learning, identify the protein NR2B as a key
>to brain function, and could lead to a drug to treat memory disorders, such as
>Alzheimer's, by increasing NR2B levels, Tsien added.
>Production of NR2B protein normally decreases with age, correlating with the
>loss of memory and learning ability commonly experienced by older people,
>The new mouse work represents a breakthrough in understanding how the brain
>functions at the molecular level, said Dr. Robert Malenka, a psychiatrist and
>behavioral sciences specialist at Stanford University School of Medicine.
>``To jump from this very elegant molecular work in a mouse model to humans
>very, very big jump,'' said Malenka. ``Nevertheless, it is a jump we can make
>and will make eventually. When we jump to humans, it will probably be a lot
>One complication is the risk that any drug that would increase NR2B levels
>could also increase the risk of stroke, because both stroke and learning are
>related to the same neurological switches in the brain, Malenka added.
>Dr. Ron McKay of the National Institute of Neurological Disorders and Stroke
>said drug companies are already investigating manipulation of NR2B levels to
>treat strokes. Any research that illuminates how NR2B works in the brain would
>be valuable in that work, he said.
>The prospect of genetically engineering smarter babies raises big ethical
>``What we are looking at is the baby steps toward a world in which we can
>design our descendants,'' said Arthur Caplan, director of the Center for
>Bioethics at the University of Pennsylvania Health System. ``I don't think
>is necessarily bad. Finding ways to repair autism or mental retardation
>associated with Down syndrome or Alzheimer's or other disabling neurological
>diseases is a very good thing.''
>Because of the inherent risks, it makes more sense ethically to begin applying
>this discovery to treating diseases and disorders, rather than trying to
>smarter babies, Caplan added.
>``I wouldn't say I would be worried quite yet about seeing hordes of tiny
>Einsteins in my neighborhood,'' he said.
>But just as parents strive to improve their children by sending them to better
>schools or giving them piano lessons, there will be those who want to
>genetically enhance their offspring, said Caplan. As in other areas of life,
>the rich would have an advantage.
>``We already have a brain gap in this society when some children go to
>kindergartens that cost $15,000 a year and other children go to kindergartens
>that don't have adequate plumbing,'' he said.
>Tsien nicknamed the smart mice ``Doogie'' after the teen-age genius in the
>television show ``Doogie Howser, M.D.''
>Using a tiny glass needle, the scientists injected a gene carrying a blueprint
>for the protein NR2B into the nucleus of a fertilized mouse egg, then
>the resulting embryo into the uterus of a mother mouse.
>Mice born with the extra gene made more NR2B than usual in their brains.
>That extra production boosted mental abilities by enhancing the function of
>brain-cell switches called NMDA receptors. The results confirm the idea,
>proposed in 1949, that these switches play a key role in learning.
>The NMDA switches require two signals to open, which fits in with the idea
>learning involves associating pairs of events or facts, like a tone and an
>electrical shock. Boosting levels of the NR2B protein kept the mouse NMDA
>switches open longer than usual.
>``If you associated food with a bell, a voice with a face, a face with a name,
>these are all associative learning, the major forms of learning in humans,''
>Tsien said. ``To associate those things you require some kind of cellular
>``It is so nice to convince ourselves that we are working in the right
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