Besides pregnancy, the uterus does not normally take much time in the medical projector. Not anymore! Scientists are beginning to investigate the complex relationship between the uterus, the ovary and the brain to better understand how removal of these organs can affect a person's health.
The rats that had their womb removed were more likely to be working with the memory of the rats who received other forms of gynecological surgery, a study published this week in the journal Endocrinology. Scientists behind the research say this is a first step in analyzing how the reproductive system – and decisions to change this system – can affect knowledge and health.
Until recently, the medical community has mostly thought of the uterus as a "baby home," says Donna Korol, a biologist studying the neural mechanisms of learning and memory at the Syrian University and not participating in the new study. However, given the organ's role in the production and regulation of hormones, it is gradually beginning to change.
"Generally, the doctrine in the field is that the non-pregnant matrix is inactive – some experts have described it as" useless, "says co-author Heather Bimonte-Nelson, a behavioral neuroscientist at Arizona State University. reproductive organs of a woman may have value beyond their reproductive capacity, so we wanted to further evaluate the effects of the uterus. "
About one-third of women in the United States will have a hysterectomy before the age of 60 and the majority of them before the physical appearance of menopause around the age of 50. It is the second most common surgery for women in the United States after Caesarean Section Unity. And in about half of these surgeries, patients will have only removed the uterus, while the other half will remove both the uterus and the uterus. Maintaining the ovaries can prevent a woman from going to a sudden, premature menopause after surgery. Ovarian removal can also be associated with an increased risk of heart disease and osteoporosis.
Previous studies have found that estrogen and other hormones produced by the ovary can help protect nervous structures in the brain while promoting cardiovascular, cutaneous, bone and urogenital health. But the uterus and the ovaries are closely linked, and the nerves connect the brain to both reproductive organs. Some studies began to examine this relationship more closely, assessing the relationship between hysterectomy and the risk of early dementia. "Let's begin to see the uterus as a regulator of brain function instead of focusing on the ovary," says Korole.
Bimonte-Nelson and Stephanie Koebele, a Bimonte-Nelson graduate student and co-author on the paper, began the experiment by performing surgery on 60 rats. One group of rats had just removed their uterus (a hysterectomy), another group had just been removed from their ovaries (a puff), a third group had removed the uterus and the ovaries and a fourth and final group had surgery, but no instruments were removed. The researchers used procedures that mimic the types of surgical procedures performed in humans.
The rats were recovered from their surgery for six weeks before Koebele and Bimonte-Nelson put them in the test. Researchers evaluated the spatial and functional memory of each rodent using a series of labyrinths that forced the rats to find platforms immersed in water and return to these platforms – or where these platforms were old. Koebele and Bimonte-Nelson wanted to assess the ability of rats to remember the navigation data and to remember the changes made by the labyrinth researchers during the experiment.
They found that the group of rats removed only from their uterus was worse in the labyrinth designed to control work memory than others. Working memory is like the short-term memory that needs to be updated, explained Bimonte-Nelson. For example, just remembering a phone number is an example of short-term memory. Having to remember this phone number and then manipulate it somehow, like adding numbers together, requires working memory.
Approximately two months after the surgery, the scientists reviewed the rats that had their ovaries. They found that while the physical structure of the ovaries did not change, the balance of hormones in the hysterectomy group and the group that had not removed any organs was slightly different indicating that the removal of only the uterus would cause light ovarian production of different hormones – after surgery.
Bimonte-Nelson and Koebele were not all surprised that this team was so different from the team that had removed both the uterus and the ovaries. The difference, explains Bimonte-Nelson, is that removing only the uterus disrupts the neurological connection of ovarian-urinary tract rather than completely removing this system. When the system is disturbed, the other organs will try to get loose to return to normal, possibly leading to hormonal changes seen by scientists in the hysterectomy group.
The short timeframe – just two months after surgery – means that scientists could not draw conclusions about the long-term effects of hysterectomy on cognition. This is also an animal model study, so that the findings are not accurately correlated with what happens to humans. Even so, research coming from this group represents the pinnacle of trying to better understand menopause, says Korole.
There is a lot to learn, but one thing is clear: It's time for the uterus to get some credit beyond the baby's ability to create.