The constant reflux and the flow of hormones that guide the menstrual cycle not only affect the reproductive anatomy. They also reshape the brain, and research gives us an overview of how it happens.
Directed by neuroscientists Elizabeth Rizor and Viktoriya Babenko from the University of California Santa Barbara, a team of researchers followed 30 women above their menstrual cycles, documenting in detail the structural changes that occur in the brain while hormonal profiles fluctuate.
The results, published in a Study evaluated by peers In 2023, suggest that structural changes in the brain during menstruation may not be limited to the regions associated with the menstrual cycle.
“These results are the first to report simultaneous changes on the brain scale in the microstructure of the human white substance and the cortical thickness coinciding with the hormonal rhythms driven by the menstrual cycle”, ” The researchers wrote.
“Strong effects of hormone brain interaction may not be limited to dense dense dense dense and dense regions of the axis of the hypothalamic-hypophymalic gonadales known.”
Menstruation generally means living some 450 periods during a lifetime, so it would be good to know the different effects they can have on the body, really.
However, although it is something that happens to half the world’s population For half their livesResearch has eaten. Who knows why. Total mystery. Seriously.
Most research on the hormonal effect on the brain has been focused on brain communication during cognitive tasks, and not on the real structures themselves.
“Cyclical fluctuations in hormones in the HPG axis exert powerful behavioral, structural and functional effects by actions on the central nervous system of mammals”, ” Rizor, Babenko and their team noted. “However, we know very little about how these fluctuations modify structural nodes and information highways of the human brain.”
The microstructure of white substance – The neural fiber fat network that transferred information between regions of gray matter – has proven to be changed with hormonal changes, including puberty, the use of oral contraception, hormonal and post -menopalty hormone therapy.
To fill the difference in menstruation in our understanding, the team took MRI Scans of their subjects for three menstrual phases: rules, ovulation and environmentluteal. At the time of each of these analyzes, the researchers also measured the hormone levels of the participants.
The results have shown that, as hormones fluctuate, the volumes of the gray and white substance also change, just like the volume of cerebrospinal fluid.
In particular, just before ovulation, when hormones 17β-estradiol And luteinizing hormone Rise, the participants’ brain has shown white matter changes suggesting a faster information transfer.
Stimulating hormone of follicleswhich rises before ovulation and helps to stimulate the ovarian follicles, was associated with a thicker gray matter.
Progesteronewhich increases after ovulation, has been associated with an increase in tissues and a decrease in the volume of cerebrospinal fluid.
What this means for the person leading to the brain is unknown, but research sets the foundations for future studies, and perhaps understand the causes of Mental health problems linked to the unusual but severe period.
A distinct study published in 2024 By an international team of scientists found that each phase of the menstrual cycle had a distinct influence on the brain as a whole, with changes through the brain and in specific regions which were also linked to the age of an individual.
“Although we do not currently point out the functional consequences or the correlates of structural brain changes, our results can have implications for hormonal alterations in behavior and cognition”, ” The researchers wrote.
“The study of relationships with the brain hormone between networks is necessary to understand the functioning of the human nervous system on a daily basis, during periods of hormonal transition and through human life.”
The results are reported in Human brain cartography.
A previous version of this article was published in October 2023.