Summary: Hormonal contraception disrupts signal transmission between cells in the prefrontal cortex of young adolescents. Hormonal birth control increases the level of stress hormones in the brain.
Source: Ohio State
Reproductive health experts view hormonal contraceptives as a good choice for teenagers because they are safe and highly effective at preventing pregnancy, but one aspect of their effects on teenage bodies remains a mystery — how and when they alter the developing brain.
A new study in young mice links synthetic hormones found in birth control pills to disordered signal transmission between cells in the prefrontal cortex, an area of the brain that continues to develop through puberty.
Compared to control mice, animals taking hormonal contraceptives produced higher levels of the stress hormone cortisone, which is similar to cortisol in humans.
The Ohio State University scientists began this line of research in the prefrontal cortex, which is involved in emotion regulation, because some previous research had linked hormonal contraceptives to depression during adolescence.
But the most important thing is to learn how birth control affects the developing brain, so that individuals can weigh the risks and benefits of their reproductive health choices.
“Birth control has a huge positive impact on women’s health and autonomy — so we’re not suggesting that teenagers shouldn’t take hormonal contraceptives,” said Benedetta Leiner, an associate professor of psychology at Ohio State.
We need to be informed about the effects of synthetic hormones on the brain so that we can make informed decisions – and if there are any risks, this is something that needs to be monitored. Then, if you decide to use hormonal birth control, pay more attention to warning signs if you know there are side effects related to mood.
A research poster was presented today (Tuesday, November 15, 2022) at Neuroscience 2022, the annual meeting of the Society for Neuroscience.
2 out of 5 teenage girls in the United States have sex between the ages of 15 and 19, and most of them use condoms. About 5% of those using birth control use hormonal contraceptives. These products are also prescribed to treat acne and heavy periods.
Despite their popularity, “little is known about how hormonal birth control affects the brain and behavior of young people,” says Kathryn Lens, an associate professor of psychology at Ohio State. “Adolescence is a very understudied period of dramatic brain change and massive hormonal change that we really don’t understand.”
The researchers administered a combination of synthetic estrogen and progesterone, found in hormonal birth control, to humans for about three weeks about a month after birth.
The researchers found that the drugs interfere with the animal’s reproductive cycle – these contraceptives stop the ovaries from producing hormones at the level necessary for egg production and make the uterine lining unsuitable for egg implantation.
Blood samples showed that the treated mice were producing more corticosterone than the untreated animals. And after exposure to and recovery from experimental stress, the corticosterone levels of the treated rats remained high. Their adrenal glands were larger, indicating that their stress hormone production was greater than that of control animals.
Analysis of gene activation markers in the animals’ prefrontal cortex showed a reduction in excitatory synapses in the brains of mice treated in that area compared to controls, but no change in inhibitory synapses – a phenomenon that results in an imbalance of normal signaling and altered behavior. Loss of excitatory synapses in the prefrontal cortex has been linked to exposure to chronic stress and depression in previous research.
“We don’t yet know what this means for the performance of certain districts. But this gives us an indication of where to look next in terms of what the practical results might be, Lens said.
The researchers are conducting further studies targeting the effects of hormonal contraceptives on the brain between puberty and late adolescence — a difficult time to study because the developing brain undergoes constant changes, Leuner said. The causes of the drug’s effects are an open question, as well.
“These are synthetic hormones, so are they damaging the brain because of their synthetic properties, or are they damaging the brain because they inhibit naturally occurring hormones?” She said. “The answer is difficult, but it is an important question.”
First author Rachel Gilfarb, a graduate student in Lehner’s lab, presented the poster. Additional Ohio State co-authors include Meredith Stewart, Abhishek Rajesh, Sanjana Ranade and Courtney Dye.
So neurodevelopment and birth control research news
Author: Emily Caldwell
Source: Ohio State
Contact: Emily Caldwell – Ohio State
Image: The image is in the public domain.
Preliminary study: The findings are presented in Neuroscience 2022