Gender and sex hormones affect the brain's pain response and more, according to n...( ues use positron-emission tomography (P...),Health

ues use positron-emission tomography (PET) brain imaging, which allows them to observe the system in action. Volunteers are scanned over a period of 20 minutes as they receive a moderately pain-causing but harmless injection of salt water in their jaw muscle. (The pain dissipates within minutes of completion of the experiment and causes no residual damage.) The studies are double-blind and placebo-controlled.

In a study involving 14 men and 14 women, Zubieta found significant differences in how the brains of men and women respond to pain. The men experienced an increase in the amount of endorphins released in certain regions of their brains during the painful state of the experiment, while most of the women showed a decrease. The participants were asked to rate the intensity and unpleasantness of the pain. Women consistently gave higher ratings for both.

All the women in this early study were in the early follicular phase of their menstrual cycle (shortly after menses) when blood levels of both estrogen and progestin are low. None were taking hormonal birth control and all had ovulated the month before. For their latest study, Zubieta and his colleagues decided to examine whether varying blood levels of estrogen would modify the response of the mu-opioid system in women. Using the same jaw pain model, the scientists studied a group of women during the follicular phase of their menstrual cycle and again during the same phase in another month--but after the women had been wearing an estrogen-releasing skin patch for a week. The results were striking. When estrogen levels were high, the women showed marked increases in their ability to release endorphins and activate the mu-opioid receptors--increases that rivaled and even surpassed those of men. The women also rated the intensity and unpleasantness of the pain lower than they had when their estrogen levels were low.

"Our studies demonstrate that some of the sex differences in an individual's
'"/>

Contact: Leah Ariniello
dawn@sfn.org
202-462-6688
Society for Neuroscience
24-Oct-2004

Page: 1 2 3 4 5 6 7
Related medicine news :

1. Gender gap for lung cancer rates narrowing
2. Gender a factor in who gets bypass surgery
3. Gender bias in child growth evaluations may miss disease in girls
4. Gender bias leaves South Asias women in poor health
5. Gender differences in brain response to pain
6. Gender and geography increase racial disparities in health care, Dartmouth study shows
7. Gender preferences in comfort foods stem from childhood
8. Gender differences apparent in psychological factors that predict later hypertension
9. Gender differences in general aviation crashes
10. Gender-specific intervention may be needed to improve diets of african-american youth
11. Gender differences in private substance abuse treatment retention