Imagine this! Someone has finally conducted an MRI scan tracking womens brains across the menstrual cycle.
Sex hormones such as estrogen and progesterone fluctuate throughout a woman’s monthly menstrual cycle. During the follicular phase at the start of the cycle, the egg is maturing and the body releases estrogen; progesterone is secreted during the luteal phase, when a fertilized egg might implant.
To see how these hormone swings influence the brain, Jean-Claude Dreher at the National Institute of Mental Health, used magnetic resonance imaging (MRI) to examine changes in female brain activity over the course of the month. The team scanned the brains of 15 women at different stages of menstruation as they played a game with hypothetical prizes of money.During the follicular phase, both the orbitofrontal cortex and the amygdala showed higher activity both when the women were anticipating a reward and when they got it. Researchers concluded that the women were probably experiencing greater feelings of reward during the first half of their menstrual cycles than they were during the second.
It isn't known whether women also get more pleasure from activities such as sex, shopping or eating chocolate during the first half of their menstrual cycle.“However, certain behaviors that are known to involve reward systems, such as drug addiction, might be enhanced during the follicular phase," says Emily Stern at Cornell University’s Weill Medical College. "Indeed, previous experiments have shown that women report getting more pleasure from cocaine and amphetamine use during the follicular phase compared to the luteal phase."
Dreher believes his findings may lead to better treatment for women with drug abuse problems, or those with mood disorders.
Source: 22:00 29 January 2007
NewScientist.com news service
Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0605569104)
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