A lady's fertility typically begins to say no in her mid-30s. This signifies that the probabilities of getting pregnant decrease rapidly every month.
For a protracted time, scientists thought that the important thing wrongdoer behind it Rapid decline In fertility Egg quality was That's comprehensible, since women are born with all of the eggs they'll ever have — and as soon as they're found. Near menopausethe variety of eggs within the ovary decreases. So does the standard of those eggs.
But a recent study shows that ovarian cells and tissues Play a big role Before fertility is lost. This finding could have major implications for a way we understand the elemental processes of reproductive aging and the way fertility could be preserved.
Studying fertility has long been difficult. Not just women's health research Historically underfundedit is usually difficult to check since the ovaries and ovarian tissues are difficult to access.
In such cases, scientists often use laboratory animals whose biology is comparable to that of humans. But that is again difficult to do, given humans are only one in all a form A handful of species Who goes through menopause. The only other animal species that undergo menopause are certain species of whales – including orcas and belugas.
But although only a number of species of animals undergo menopause, many animals share the identical ovarian biology as humans. It is for that reason that the research team began their investigation using mice on the reproductive age.
The research team took ovarian tissue from young and old mice, and compared it to ovaries from women of their 20s, 30s and 50s. They then used 3D imaging and compared the gene profiles of cells within the ovaries to create detailed maps of various cell types and their functions throughout life.
They found each similarities and differences in ovarian function and aging between mice and humans. These early results were necessary in confirming that mice could be useful as models when studying human fertility.
They found that older eggs were more similar in humans and mice than younger eggs. Also occurs in human and mouse ovaries Similar cell types which support egg development.
In humans, granulosa cells surround the egg and produce estrogen. Mice appear to have the same cell, which performs the same function.
However, THECA cells, which produce testosterone in humans and stimulate granulosa cells, appear to operate in another way in mice.
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The researchers found evidence that a special nerve support cell, called a glial cell, is present in each mouse and human ovaries — and that this cell develops early in fetal life. In each humans and mice, glial cells appear to stimulate the ovary to provide eggs.
They also genetically manipulated the event of glial cells in mice and mimicked what the ovaries looked like. Polycystic ovary syndrome (PCOS) Doing this resulted in additional early-stage eggs being produced within the ovary—but they didn’t mature properly. The results provide hope that mouse models may help develop latest, much-needed treatments for PCOS.
By comparing ovaries in young and old, the researchers found that the tissue structure is different in humans and mice. Humans create spaces between the eggs – and the ovary hardens as more fibrous tissue is placed, perhaps because Tissue regeneration and repair More than a lady's reproductive life.
These changes in ovarian cells and tissues may explain why human ovaries are relatively old in comparison with other species. The study's findings also suggest that it's not only the egg, however the broader ecosystem of the ovary, that contributes to the decline in fertility after 30.
Being in a position to use animal models to research women's health will advance our understanding of conditions like PCOS and infertility, which have historically been underfunded and under-researched. This will allow researchers to higher study reproductive diseases that affect women and develop latest drugs that may treat these debilitating conditions.
This knowledge improves the understanding of the underlying processes of ovarian aging that can enable higher diagnosis and treatment of infertility.