Public release date: 15-Feb-2003
Contact: Monica Amarelo Ginger Pinholster
Prior to 13 February, 202-326-6440
As of 13 February, 303-228-8301
American Association for the Advancement of Science
http://www.aaas.org/
Talking to the animals?
New findings help explain vocal learning may guide the search for the
brain's language center
"To a teacher of languages there comes a time when the world is but a place
of many words and man appears a mere talking animal not much more wonderful
than a parrot."
--Joseph Conrad (1857-1924), Polish-born British novelist, from Under
Western Eyes, pt. 1, prologue (1911)
DENVER, CO - As the late novelist Joseph Conrad once suggested, people may
indeed have more in common with vocal-learning birds like songbirds and
parrots than we have previously assumed.
In songbirds capable of vocal learning, or imitating the sounds they hear,
new findings reveal a highly specialized pattern in the genetic expression
of certain brain receptors. These same receptors for the neurotransmitter,
glutamate, are also found in mammals, neurobiologist Erich D. Jarvis noted
during the annual meeting of the American Association for the Advancement of
Science (AAAS).
If further research shows the same specialized receptor pattern in people,
the research may help pinpoint the brain's precise language centers-a first
step toward better understanding language loss associated with strokes,
lesions or head injuries. The work, by Jarvis, his student and first author
Kazuhiro Wada at Duke University and colleagues Hironobu Sakaguchi and
Masatoshi Hagiwara in Japan, is now pending review by the Proceedings of the
National Academy of Sciences (PNAS).
"Although it might seem far fetched, I would not be surprised if these
ancient receptors could someday help us identify the entire system of brain
regions for vocal learning and language in humans in a way that hasn't been
done before," said Jarvis, an assistant professor in Duke's Department of
Neurobiology.
Like a modern-day Dr. Doolittle, Jarvis-winner of the prestigious Alan T.
Waterman Award, the National Science Foundation's highest honor for a young
scientist or engineer-seeks to understand animal "language." He's
investigating what structures and molecular events in the brain give six
groups of animals a capacity for vocal learning. Imitating the sounds we
hear is a rare trait, shared only by certain birds (parrots, songbirds and
hummingbirds) and a few mammals (bats, cetaceans in the whale/dolphin family
and humans).
As he studies the neural mechanisms behind vocal learning, Jarvis is also
pursuing a key question in evolutionary biology: Did the trait of vocal
learning emerge independently in all six vocal-learning groups within the
past 65 million years, as a now-dominant theory suggests? Or, did all vocal
learners share a common ancestor with the trait, but then diverge as a
result of subsequent, independent mass extinctions of vocal learning among
various animals, including non-human primates? Though this question remains
a mystery for now, Jarvis' latest work suggests that the evolution of vocal
learning was accompanied by divergent, specialized expression of an ancient
gene family in different vocal learning animals. Further, the diversity of
expression seems to depend on the complexity of the animal's vocal syntax.
"Whether independent or dependent from a common ancestor, diversity of
neurotransmitter receptors in their vocal systems is probably not an
evolutionary cause of vocal learning, but a consequence of it, as diverse
species-specific specializations can be assumed recent and ongoing
evolution," Jarvis, Wada and colleagues wrote in their pending PNAS paper.
Moreover, they added: "With diverse specialization as a rule, it is not too
far a stretch to suggest that vocal-learning mammals, including humans, also
evolved diverse specialized glutamate receptor expression in vocal areas of
their cerebrums and that these are related in part to vocal syntax
complexity."
Jarvis received his doctoral degree from The Rockefeller University in 1995.
He was one of 52 African American men out of more than 4,300 biologists to
receive a Ph.D. in the United States that year. His own pathway to success
was inspired by his mother, a woman with an ambitious spirit, and his late
father, a talented man who struggled with schizophrenia and periodic
homelessness while Erich was a child in New York City's Harlem community.
His father's eclectic interests and appreciation for the natural world
helped to shape Erich's unique, interdisciplinary approach to his research,
making him-as former NSF Director Rita Colwell once said-"truly a gem" and
"the epitome of the modern scientist, crossing between disciplines and
ideas."
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Advance interviews possible upon request.
This research project was funded mostly by a National Science Foundation
grant.
The American Association for the Advancement of Science (AAAS) is the
world's largest general scientific society, and publisher of the journal,
Science. Founded in 1848, AAAS serves 134,000 members as well as 272
affiliates, representing 10 million scientists.
For more information on the AAAS, see the web site, www.aaas.org. Additional
news from the AAAS Annual Meeting may be found online at www.eurekalert.org.
MEDIA NOTE: A newsbriefing featuring Dr. Jarvis will take place at the
Marriott, at 8:00 a.m. Mountain Time, Saturday, 15 February, in Denver
Ballrooms 3 & 5. The newsbriefing is part of the AAAS Women & Minorities
Breakfast, which will run from 7:00 a.m. until 9 a.m. Press registration is
located in the Colorado Convention Center, C-101. All reporters must have
press badges to attend this newsbriefing.
AAAS is the world's largest general scientific society, dedicated to
"Advancing science . Serving society."
http://www.eurekalert.org/pub_releases/2003-02/aaft-ttt020303.php
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