The transition to menopause, known as peri-menopause, can bring a wide range of debilitating neurological symptoms in up to 75% of women.
Among the most significant symptoms are depression and anxiety, but the reasons for why this happens remain poorly understood.
University of Otago neuroendocrinologists and physiologists have received $272,851 from the Neurological Foundation of New Zealand to investigate the issue.
Centre for Neuroendocrinology Research principal investigator Dr Rosie Brown said the team typically looked at how hormones affected women’s mood and behaviour during pregnancy and in the early postpartum period.
"But we found that when we were talking to women, one of the things that they kept saying to us was, the other time they experienced challenges with their mood was during the whole peri-menopause window.
"So we decided that this was something that we would also like to start looking into."
During their earlier research on hormones in pregnancy and early postpartum, she said they identified a key hormone — estradiol.
"Two of the key hormones in women are estrogens, and the main estrogen that’s active in women is called estradiol.
"What we saw during our work is that if you remove estradiol in female mice, their motivation to want to be with offspring was greatly diminished."
She theorised when estradiol levels dropped, the brain may rewire, leading to mood disorders.
"That made us think about women and when in their life they would normally see estradiol levels lowered.
"It would normally happen in peri-menopause and menopause.
"So this research kind of all stemmed out of a pregnancy study, where we saw how important estradiol was for motivation and reward, and we thought this is probably more important than just wanting to be with offspring."
Using a mouse model, she said the new study would explore how and where estradiol acted in the brain, and whether replacing it during peri-menopause could restore normal brain function.
"At the moment, there’s menopause hormone therapy that gives back estrogen and progesterone to help some of the symptoms that occur during peri-menopause.
"Usually it’s given for things like hot flushes. What it’s not recommended for yet, is for mood disorders."
The researchers wanted to see if the hormones helped with some of the mood effects.
"The one thing we would be keen to look at is actually the interplay of the different hormones that are changing.
"And it may mean that you need to have different combinations of the hormones that you’re essentially restoring or replacing, that can target some of those mood effects.
"That’s something that we can test in the animal model — what is actually optimal to prevent or to treat some of these effects that can occur."
