A systematic scan of the brain 32-year-old woman during the menstrual cycle proved that some structures in the brain change in size. Scientists from the max Planck Institute every two days, had MRI of the brain to the same woman for one month. For measurement accuracy, the time of the study was also the same, writes The Daily Mail.
The researchers found that during ovulation, the size of the hippocampus increased. This structure of the brain responsible for memory, the formation of emotions and a person's mood. When hormones come to the normal values, and menstruation, the size of the hippocampus, on the contrary, decreased.
Scientists suggest that these changes are associated with the levels of the hormone estrogen. Progesterone (another female hormone) this effect is not provided. Opening partly explains the reason for mood changes in women during ovulation and menstruation. It is possible that further study will help to better understand the mechanisms of development of premenstrual syndrome.