IS IT that time of the month? Unusual depression? Mood swings? If you experience such changes before menstruation, it might be because an emotional buffer zone in your brain is not working as it should.
David Silbersweig and colleagues at the Weill Medical College of Cornell University, New York, used functional magnetic resonance imaging to scan the brains of 12 women whose moods remained steady throughout their menstrual cycles. From 1 to 5 days before menstruation, and 8 to 12 days after, the women鈥檚 brains were scanned as they were shown printed words with either negative, neutral, or positive connotations -for instance 鈥渞ape鈥�, 鈥渂ookcase鈥�, 鈥済entle鈥� and 鈥渄elighted鈥�.
At the same time, the women performed tasks such as pushing a button depending on whether the word was written in normal or italic font. The scans showed that the orbitofrontal cortex, part of the brain involved in controlling emotions and regulating motivation, was more active in the days before menstruation. After menstruation, it was relatively inactive (Proceedings of the National Academy of Sciences, vol 102, p 16060).
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Silbersweig says that the difference in brain activity may 鈥渂uffer鈥� hormonal changes in these women, helping them to maintain a consistent emotional state.
