This is the twice-per-month electronic newsletter for basic, preclinical and translational research news related to the Johns Hopkins School of Medicine. Please forward freely. Direct comments or questions to Joanna Downer, PhD, in the Office of Corporate Communications (410-614-5105, jdowner1@jhmi.edu).
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*** Basic Science Town Meeting June 30 at 2 pm ***
IN THIS ISSUE:
RESEARCH HIGHLIGHTS:
+ Auditory Cortex Neurons Can Discharge for a Long Time
+ Nitric Oxide Helps Regulate Function of Glutamate Receptors
+ Transfer RNA Triggers Its Own Acceptance
NEWS BRIEFS:
Basic Science Town Meeting June 30
Save the Date: 100+ Women Professors Celebration Nov. 1
IN THE NEWS:
Joshua Mendell in The New York Times
Chi Dang on MSNBC.com
Noel Rose in the New York Times
Christopher Ruff in the Baltimore Sun
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Do you have an interesting research finding about one month from publication or presentation? Send manuscripts to Joanna Downer at jdowner1@jhmi.edu or fax to 410-614-8951. Information about awards and honors received by laboratory personnel and others is welcomed also.
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RESEARCH HIGHLIGHTS:
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5/19/05
Auditory Cortex Neurons Can Discharge for a Long Time
Through their studies of awake animals, Johns Hopkins scientists might have resolved a paradox in our understanding of hearing.
Instead of exhibiting only transient responses to sound stimulation, awake primates' auditory cortex can in fact give sustained discharges for long periods of time, the researchers report in the May 19 issue of Nature. This is more consistent with the auditory cortex's role in processing complex sounds such as human speech and music.
"The experiments that gave rise to current views of mammalian auditory cortex were based on studies in anaesthetized animals," says Xiaoqin Wang, PhD, associate professor of biomedical engineering and neuroscience in Johns Hopkins' Institute for Basic Biomedical Sciences. "We studied awake marmosets, and that made all the difference."
He adds that sustained responses they observed suggest how a sound "picture" can be built up. "Select neurons fire for the duration of their 'preferred' sound, but the responses of other neurons fade after the onset of what, for them, is a non-preferred stimulus," says Wang. "Having short and long responses to sound increases the possible combinations and helps explain why we can interpret very complex sounds."
Other authors on the paper are Thomas Lu, Ross Snider and Li Liang, all with Laboratory of Auditory Neurophysiology in the Biomedical Engineering Department at The Johns Hopkins University. Snider is now an assistant professor at Montana State University at Bozeman. The research was funded by the National Institutes of Health and a U.S. Presidential Early Career Award for Scientists and Engineers.
Nature 19 May 2005;435(7040):341-346.
http://www.nature.com/nature/journal/v435/n7040/full/nature03565.html
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5/19/05
Nitric Oxide Helps Regulate Function of Glutamate Receptors
Researchers at Johns Hopkins have discovered that the binding of nitric oxide (NO) to the protein NSF (N-ethylmaleimide sensitive factor) helps regulate glutamate receptor function in the mouse brain.
These and other Hopkins scientists recently showed that NSF was modified by NO and identified NSF as a key regulator of glutamate receptors known as AMPA receptors. Taking these earlier findings a step further, the new study, published in the May 19 issue of Neuron, suggests that nitric oxide's binding to NSF enhances NSF's binding to GluR2, a subunit of the brain's most common glutamate receptor.
"This study demonstrates that the major excitatory receptors in the brain can be regulated by the gaseous transmitter NO," says Richard Huganir, PhD, professor of neuroscience in the Institute for Basic Biomedical Sciences at Johns Hopkins. "This was very surprising and suggests this regulation may be critical for modulating the strength of neurons' connections, a phenomenon called synaptic plasticity that underlies learning and memory."
The study also shows that nitric oxide helps NSF redistribute various subunits of the glutamate receptor on neurons, an ability of NSF Huganir and his colleagues had recently reported. Because availability of glutamate receptors helps determine whether and how a neuron can react to glutamate, understanding the control of receptor and subunit distribution should help unravel steps in learning and memory, says co-author Solomon Snyder, PhD, Distinguished Service Professor of Neuroscience, Pharmacology and Psychiatry and director of neuroscience.
Neuron 19 May 2005;46(4):533-540.
http://www.neuron.org/content/article/fulltext?uid=PIIS0896627305003132
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5/20/05
Transfer RNA Triggers Its Own Acceptance
To help ensure perfect proteins, the right amino-acid-carrying transfer RNA actually triggers its own acceptance into bacteria's protein-building machinery, Johns Hopkins researchers report in the May 20 issue of Science.
"Transfer RNA isn't just a bridge between messenger RNA and the protein, it really is a functional player," says Rachel Green, PhD, professor of molecular biology and genetics in Johns Hopkins' Institute for Basic Biomedical Sciences. "When the right transfer RNA enters the ribosome, it makes the ribosome go shooting through the next steps in the process."
Other researchers had shown that once the right transfer RNA enters the ribosome, a chemical change takes place in a distant part of the ribosome and causes the transfer RNA's amino acid to be transferred to the growing protein chain. Now, Green and graduate student Luisa Cochella have learned that the transfer RNA itself speeds that chemical change.
For this work, Cochella was awarded the 2005 Alicia Showalter Reynolds Research Award at the 28th annual Young Investigators' Day at the Johns Hopkins School of Medicine. The research was funded by the National Institute of General Medical Sciences and the Howard Hughes Medical Institute.
Science 20 May 2005;308(5725):1178-1180.
http://www.sciencemag.org/cgi/content/abstract/308/5725/1178
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NEWS BRIEFS:
Basic Science Town Meeting June 30 -- The next Basic Science Town Meeting will be Thursday, June 30, at 2 p.m. in Preclinical Teaching Building Room 517.
Save the Date: 100+ Women Professors Celebration Nov. 1 -- On Tuesday, Nov. 1, The Johns Hopkins University School of Medicine, the Office of the Dean and the Women's Leadership Council will host a celebration for reaching the milestone of having more than 100 women faculty promoted to the rank of professor since the school's founding in 1893. The event will also honor the legacy of Mary Elizabeth Garrett, who provided the endowment to fund the medical school and who insisted women be admitted from the very beginning. Linda Buck, PhD, 2004 Nobel Laureate in Medicine, is confirmed as a keynote speaker. Keep an eye on http://www.hopkinsmedicine.org/wlc for more information.
IN THE NEWS:
Joshua Mendell on microRNAs and cancer in The New York Times. "Papers find genetic link to growth of tumors," by Andrew Pollack, the New York Times, June 9, 2005.
http://www.jhu.edu/clips/2005_06/09/papers.html
(Must be at a Hopkins computer to access this page.)
Chi Dang on microRNAs on MSNBC.com. "Scientists find key to stem cell immortality," by Alan Boyle, MSNBC.com, June 9, 2005.
http://www.jhu.edu/clips/2005_06/09/stem.html
(Must be at a Hopkins computer to access this page.)
Noel Rose on autoimmune disease in the New York Times. "Trying to shut off the body's friendly fire," by Andrew Pollack, The New York Times, June 5, 2005.
http://www.jhu.edu/clips/2005_06/06/trying.html
(Must be at a Hopkins computer to access this page.)
Christopher Ruff on drawing extinct creatures in the Baltimore Sun. "Drawn to Dinosaurs," by Dennis O'Brien, The Baltimore Sun, June 3, 2005.
http://www.jhu.edu/clips/2005_06/03/drawn.html
(Must be at a Hopkins computer to access this page.)
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John Sales contributed to the Research Highlights for this issue.
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--JHMI--
