Girls exercise better without boys

Chicago Sun-Times, Sep 2, 2005 by Nanci Hellmich

High school girls are more likely to exercise vigorously if they're in girls-only gym classes offering activities such as dancing, aerobics and brisk walking, according to a new study in September's American Journal of Public Health.

Public health officials are concerned by other research showing that girls become much less physically active during their teen years. Many don't exercise at all by the time they reach 18 or 19 -- yet children should be active at least an hour a day, according to government guidelines.

Russell Pate, professor of exercise science at the University of South Carolina, says girls long have been given exercise classes designed more for boys, and "a lot of them don't like it very much."

During the 1950s, '60s and early '70s, girls and boys usually were separated in junior high and high school programs, but "after Title IX was put into place by the mid-70s, coed physical education became the more common approach," says Judy Young of the American Alliance for Health, Physical Education, Recreation and Dance, a professional organization that includes teachers, researchers and administrators.

(Source: Chicago Sun Times)

Genetic way to tame Casanovas

Emory University press release

Yerkes and CBN Researchers Make Promiscuous Animals Monogamous by Manipulating Genes Researchers at the Yerkes National Primate Research Center of Emory University and Atlanta's Center for Behavioral Neuroscience (CBN) have found transferring a single gene, the vasopressin receptor, into the brain's reward center makes a promiscuous male meadow vole monogamous. This finding, which appears in the June 17 issue of Nature, may help better explain the neurobiology of romantic love as well as disorders of the ability to form social bonds, such as autism. In addition, the finding supports previous research linking social bond formation with drug addiction, also associated with the reward center of the brain.

In their study, Yerkes and CBN post-doctoral fellow Miranda M. Lim, PhD, and Yerkes researcher Larry J. Young, PhD, of the Department of Psychiatry and Behavioral Sciences at Emory University's School of Medicine and the CBN, attempted to determine whether differences in vasopressin receptor levels between prairie and meadow voles could explain their opposite mating ehaviors. Previous studies of monogamous male prairie voles, which form lifelong social or pair bonds with a single mate, determined the animals' brains contain high levels of vasopressin receptors in one of the brain's principal reward regions, the ventral pallidum. The comparative species of vole, the promiscuous meadow vole, which frequently mates with multiple partners, lacks vasopressin receptors in the ventral pallidum.

The scientists used a harmless virus to transfer the vasopressin receptor gene from prairie voles into the ventral pallidum of meadow voles, which increased vasopressin receptors in the meadow vole to prairie-like levels. The researchers discovered, just like prairie voles, the formerly promiscuous meadow voles then displayed a strong preference for their current partners rather than new females. Young acknowledges many genes are likely involved in regulating lifelong pair bonds between humans. "Our study, however, provides evidence, in a comparatively simple animal model, that changes in the activity of a single gene profoundly can change a fundamental social behavior of animals within a species."

According to previous research, vasopressin receptors also may play a role in disorders of the ability to form social bonds, such as in autism. "It is intriguing," says Young, "to consider that individual differences in vasopressin receptors in humans might play a role in how differently people form relationships."

And, Lim adds, past research in humans has shown the same neural pathways involved in the formation of romantic relationships are involved in drug addiction. "The brain process of bonding with one's partner may be similar to becoming addicted to drugs: both activate reward circuits in the brain." The researchers' next step is to determine why there is extensive variability in behaviors among individuals within a species in order to better understand the evolution of social behavior.

The Yerkes National Primate Research Center of Emory University is one of eight National Primate Research Centers funded by the National Institutes of ealth. The Yerkes Research Center is a multidisciplinary research institute recognized as a leader in biomedical and behavioral studies with nonhuman primates and rodents. Yerkes scientists are on the forefront of developing vaccines for AIDS and malaria, and treatments for cocaine addiction and Parkinson's disease.

The Center for Behavioral Neuroscience, a National Science Foundation Science and Technology Center consisting of more than 90 neuroscientists at eight metro Atlanta colleges and universities, conducts research on the basic neurobiology of complex social behaviors. Its programs have led to a breakthrough treatment for anxiety-related disorders and new understanding of the potential roles of the neurochemicals vasopressin and oxytocin in autism.

(Source: Emory University press release)

New Male Contraceptive

American Scientist

November 16, 2004 - Vol. 2 , No. 46

Shot Makes Monkeys Momentarily Infertile

An experimental vaccine given to male macaque monkeys temporarily sapped their fertility, pushing the potential for a new contraceptive for men a step closer to reality, according to new research written up in the journal Science. The novel treatment, dubbed “immunocontraception,” worked like this: Every three weeks, researchers injected nine monkeys with a protein called Eppin, which is involved in the production of sperm. In immunological response, seven of those monkeys created antibodies, which then attacked the Eppin and rendered the monkeys sterile. Five of the sterile monkeys regained their ability to conceive once the immunizations stopped.

Turning that success in monkeys into a new contraceptive for men, and improving its efficacy, will take lots of further research, time and money, said lead researcher Michael O’Rand, a cell and developmental biologist at the University of North Carolina at Chapel Hill. To get there, O’Rand and his colleagues will need a clearer understanding of the mechanics at work. Their best guess: “We think the immunocontraception works by preventing the sperm from freeing itself from the seminal fluid to make its way to the uterus and oviducts to fertilize the egg,” O’Rand told Associated Press.

Right now, the list of male contraceptives stops after condoms and vasectomies. So a good amount of research has gone toward developing hormone-based contraceptives, and those actually may be closer to reality. Previous attempts at a vaccine that shackles sperm have gone a bit too far. But the effects here were reversible. Researchers believe that’s because Eppin, which serves as a coating for sperm, literally caps the process of sperm production. Because Eppin is so late to the male reproductive party, the antibodies don’t damage the male testes.

Susan Benoff, a former president of the Society for Male Reproduction, pointed out to USA Today that for immunocontraception to catch on someday, some psychological hurdles will have to be overcome. Not only might men be reluctant to give up their fertility for a time, said Benoff, but women would have to make a leap of faith. "If you are the woman," said Benoff, "you are the one who’s going to be pushing out the 8-pound bowling ball, so you really have to trust that he’s going to do what he says he’s going to do."

(Source: American Scientist)