Newswise — Researchers at UT Southwestern Medical Center have overturned the current theory of how a pheromone works at the molecular level to trigger behavior in fruit flies.
The finding, if it proves true in other species, might lead to new ways to manipulate the actions of harmful insects, the researchers said.
They found that the pheromone, which affects mate recognition and sexual behavior, does not directly attach to nerve cells, as was previously thought. Rather, the pheromone first docks onto a free-floating protein in the insect’s antennae called LUSH.
This docking action causes LUSH to change shape. The reshaped protein, not the pheromone itself, is what activates the nerve cells, the researchers found. Their findings show that the pheromone only indirectly controls the animal’s behavior.
“If we can inhibit this molecular interaction, we might be better able to control pests that harm crops, carry malaria and so forth,” said Dr. Dean Smith, associate professor of pharmacology and neuroscience at UT Southwestern and senior author of the study, which appears online today and in Friday’s issue of the journal Cell.
Pheromones are molecules that an organism releases to trigger a specific behavior in other members of its species. Insects make wide use of pheromones to attract mates, signal the location of food, warn of attackers and provide other signals. Detection of pheromones is so sensitive that, in some cases, a single molecule is enough to trigger a response.
In agriculture, pheromones for some pest species are already used to protect crops by disrupting reproduction.
The current study used the fruit fly Drosophila melanogaster and focused on a pheromone called cVA (11-cis vaccenyl acetate). Only male flies produce cVA, but both males and females react to it. It is involved in clustering, mate recognition and sexual behavior.
The researchers examined the interaction of cVA with a type of nerve cell called T1 in the antennae of Drosophila. Holes in the antenna allow cVA to enter a fluid-filled chamber that surrounds these nerve cells. When the pheromone enters the antenna, the nerve cells fire.
The fluid surrounding the nerve cells also contains the LUSH protein, which was already known to bind to cVA. The prevailing theory is that LUSH proteins act as a carrier, picking up any cVA molecules that enter the antenna, transporting them to the nerve cells and releasing the pheromone molecules to bind directly to the nerve cells, Dr. Smith said.
In their experiments, Dr. Smith’s group examined the nerve cells’ firing patterns in genetically altered flies. The researchers also created variations of LUSH with varying abilities to change shape. One variant of LUSH, designed to mimic the shape it takes when bound to cVA, was capable of stimulating the nerve in the complete absence of the pheromone.
“LUSH is clearly important for activating the nerve,” Dr. Smith said. “The nerve cell’s receptor is designed to work only when cVA and LUSH are bound together. It’s a very unusual pathway that allows even single pheromone molecules to activate the nerves.”
The researchers are further examining the interaction between the pheromone and the nerve cell receptors.
Dr. Smith said if pheromone systems work this way in other insect species, researchers might be able to design compounds that block the action of pheromones, allowing them to manipulate and control pest behavior, including controlling mating and reproduction.
Dr. Tal Soo Ha, postdoctoral researcher in pharmacology at UT Southwestern, and researchers from the University of Colorado Denver also participated in the study.
The work was funded by the National Institutes of Health, with further support from the Howard Hughes Medical Institute and the University of Colorado Cancer Center.
Dr. Dean Smith -- http://www.utsouthwestern.edu/findfac/professional/0,2356,16780,00.html
Tuesday, August 26, 2008
Secrets of Pheromone Detection
Thursday, August 21, 2008
Biofeedback Contributes to gold Medal Performance
Newswise — When Abhinav Bindra took home the gold medal in the 10 metres air Skills of a Shooter Sport psychologist Timothy Harkness used biofeedback training to help Bindra Biofeedback and Optimal Functioning Biofeedback is used primarily for treatment of various medical disorders, including ADD/ADHD, chronic pain, headaches, and other. But it is gaining prominence in a more proactive capacity as well. Individuals, ranging from athletes to artists to business leaders and more, are tapping into the benefits of biofeedback to optimize health, mental, physical, emotional and spiritual functioning, and peak performance fields. Biofeedback training can help individuals optimize brain function for peak mental performance. It empowers people to achieve their goals, be they Olympic level or within day-to-day activities. It helps users manage their mental and emotional states and how these may help or hinder achievement of goals.
rifle event at the Beijing Olympics, he not only earned the first individual
medal ever for India, he also demonstrated how biofeedback training can be
an integral part of performance optimization at the highest level.
Dead aim is only the tip of the iceberg when it comes to the skills needed
to excel at shooting. In addition, shooters need controlled breathing and
heart rate, no excess tension in their muscles, no interior monologue, and
sharp focus and good reactions to trigger at the moment when the sight image
is correct.
master control over all these areas. Using the a FlexComp Infiniti hardware
system with BioGraph 4.0 software, Harkness joined a team of shooting
coaches, a physician, chiropractor, dietician and physiotherapist to prepare
Bandra for the 2008 competition. The result was that an already
world-champion athlete was able to push his skills and focus even higher. He
achieved his personal goal and earned the only medal for India during the
2008 games.
Biofeedback is a process that enables an individual to learn how to change
physiological activity for the purposes of improving health and performance.
Precise instruments measure physiological activity such as brainwaves, heart
function, breathing, muscle activity, and skin temperature. These
instruments rapidly and accurately "feed back" information to the user. The
presentation of this information - often in conjunction with changes in
thinking, emotions, and behavior - supports desired physiological changes.
Over time, these changes can endure without continued use of an instrument.
Wednesday, July 9, 2008
Childhood Diabetes Verging on Epidemic
Concerns about children’s health in America is growing along with their waistlines, and medical experts fear that the childhood obesity epidemic could lead to large numbers of younger adults developing type 2 diabetes, causing serious and lasting health complications for future generations of Americans.
In an article in the July issue of the Archives of Pediatric & Adolescent Medicine, University of Michigan C.S. Mott Children’s Hospital pediatric endocrinologist Joyce Lee, M.D., M.P.H, warns that the most damaging effects of childhood obesity have yet to surface, and will likely result in an epidemic of type 2 diabetes among young adults, leading to a greater number of diabetes complications, and ultimately, lower life expectancy.
“The full impact of the childhood obesity epidemic has yet to be seen because it can take up to 10 years or longer for obese individuals to develop type 2 diabetes,” says Lee, a member of the Child Health Evaluation and Research (CHEAR) Unit at Mott. “Children who are obese today are more likely to develop type 2 diabetes as young adults.”
Common Vitamin Supplement Could Prevent Cancer
Early laboratory research has shown that resveratrol, a common dietary supplement, suppresses the abnormal cell formation that leads to most types of breast cancer, suggesting a potential role for the agent in breast cancer prevention. Resveratrol is a natural substance found in red wine and red grapes. It is sold in extract form as a dietary supplement at most major drug stores.
“Resveratrol has the ability to prevent the first step that occurs when estrogen starts the process that leads to cancer by blocking the formation of the estrogen DNA adducts. We believe that this could stop the whole progression that leads to breast cancer down the road,” said Eleanor G. Rogan, Ph.D., a professor in the Eppley Institute for Research in Cancer and Allied Diseases at the University of Nebraska Medical Center.
Tuesday, July 1, 2008
Dose of Vitamin A Keeps Infant Mortality Away
A single, oral dose of vitamin A, given to infants shortly after birth in the developing world can reduce their risk of death by 15 percent, according to a study conducted by researchers at the Johns Hopkins Bloomberg School of Public Health. The study is published in the July 2008 edition of the journal Pediatrics.
“It has long been known that vitamin A supplementation can reduce mortality in children over 6 months of age. Our study showed that vitamin A given at birth can also improve infant survival within the first 6 months of life,” said Rolf D.W. Klemm, DrPH, MPH, the study’s lead author and a researcher with the Bloomberg School’s Center for Human Nutrition.