Scientists at the Francis Crick Institute have revealed how hormones associated with pregnancy, particularly estrogen and progesterone, alter the neurological structures in female mice. This neural alteration heightens maternal instincts even before the offspring are born. The research opens up the possibility of analogous long-term cerebral changes in human pregnancies due to the same hormonal interactions.
The team at the Francis Crick Institute has demonstrated that hormones related to pregnancy essentially restructure the brain, equipping mice for maternal responsibilities. The study, published on October 5 in the journal Science, found that estrogen and progesterone influence a specific subset of neurons, activating maternal behaviors even prior to the birth of the young. These adjustments led to enhanced and more focused reactions toward the young.
While it has been commonly accepted that virgin female rodents do not engage much with offspring, maternal rodents invest a significant amount of time in caregiving. Initially, it was believed that the hormonal changes occurring during childbirth were the primary drivers of this maternal behavior. However, earlier studies indicated that even rats that underwent Caesarean sections, as well as virgin mice exposed to pregnancy hormones, exhibited such maternal tendencies. This led to the suggestion that hormonal alterations taking place during pregnancy could be more critical.
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Mechanistic Insight into Hormonal Influence on Neuronal Activity
The recent investigation discovered that female mice exhibited augmented parental behavior in late stages of pregnancy, without requiring exposure to the young. Researchers identified that a specific type of nerve cells, known as galanin-expressing neurons, located in the medial preoptic area (MPOA) within the hypothalamus—a brain region linked to parenting—were affected by estrogen and progesterone.
Electrophysiological recordings demonstrated that estrogen concurrently decreased the baseline neuronal activity while increasing their excitability. Progesterone, on the other hand, altered the neuronal inputs by adding more synapses, which are the communication junctions between neurons.
Making these neurons resistant to hormonal influence entirely eliminated the emergence of parental behaviors during pregnancy. Consequently, mice failed to display maternal tendencies even post-birth, indicating a crucial phase in pregnancy when these hormones are most effective.
Some of these cerebral changes persisted for at least a month following childbirth, while others appeared to be lasting, indicating that pregnancy can induce long-term modifications in the female brain.
Expert Commentary
Jonny Kohl, who heads the State-Dependent Neural Processing Laboratory at the Crick, stated, “We are aware that the female physiology undergoes transformations during pregnancy to get ready for nurturing the young. One instance is the onset of milk production, which begins well before childbirth. Our study reveals that analogous preparations are also occurring within the brain.”
Rachida Ammari, a postdoctoral fellow at the Crick, alongside PhD student Francesco Monaca as first authors, mentioned, “Our work indicates that there exists a flexible period in the brain that prepares for upcoming behavioral challenges. These neurons receive substantial inputs from other brain regions, and we aim to comprehend the origin of this new information.”
The researchers speculate that similar neurological rewiring could occur in human pregnancies, as identical hormonal changes are expected to affect the same brain regions. This could shape parental behaviors in conjunction with environmental and social factors.
Reference: “Hormone-mediated neural remodeling orchestrates parenting onset during pregnancy” by Rachida Ammari, Francesco Monaca, Mingran Cao, Estelle Nassar, Patty Wai, Nicholas A. Del Grosso, Matthew Lee, Neven Borak, Deborah Schneider-Luftman, and Johannes Kohl, published on 5 October 2023 in Science.
DOI: 10.1126/science.adi0576
Frequently Asked Questions (FAQs) about Pregnancy hormones and brain restructuring
What is the primary focus of the research conducted by the Francis Crick Institute?
The primary focus of the research is to understand how pregnancy hormones, specifically estrogen and progesterone, alter the brain structure in female mice. The study aims to explore how these hormonal changes affect maternal instincts and behaviors even before the offspring are born.
Who are the main hormones implicated in these changes?
The hormones primarily implicated in these changes are estrogen and progesterone.
What is the role of estrogen and progesterone in brain restructuring?
Estrogen concurrently lowers the baseline activity of certain neurons while making them more excitable. Progesterone alters the neuronal inputs by adding more synapses, the communication junctions between neurons.
Does this research suggest that similar changes could happen in human pregnancies?
Yes, the researchers speculate that similar neural rewiring could occur during human pregnancies, as the same hormonal changes are expected to impact identical areas of the human brain.
What neurons are specifically affected by these hormonal changes?
A specific type of nerve cells known as galanin-expressing neurons, located in the medial preoptic area (MPOA) within the hypothalamus, are affected by estrogen and progesterone.
What were the observations regarding maternal behavior in mice?
The study found that female mice exhibited augmented parental behavior during late stages of pregnancy without requiring prior exposure to the young.
What do experts say about the broader implications of these findings?
Experts like Jonny Kohl and Rachida Ammari suggest that there is a flexible period in the brain during pregnancy that prepares for upcoming behavioral challenges. These changes indicate broader preparations occurring within the brain for nurturing the young.
What are the publication details of this research?
The research findings were published on October 5 in the scientific journal Science, with the DOI: 10.1126/science.adi0576.
Are these brain changes temporary or permanent?
Some of the observed cerebral changes persisted for at least a month following childbirth, while others appeared to be lasting, suggesting that pregnancy can lead to long-term modifications in the female brain.
Where can one find the original study?
The original study was published in the journal Science and can be accessed using the DOI: 10.1126/science.adi0576.
More about Pregnancy hormones and brain restructuring
- Francis Crick Institute
- Science Journal
- Hormones and Behavior
- Parental Behavior Studies
- Neural Plasticity and Behavior
- Effects of Estrogen on the Brain
- Progesterone and Neurological Function
- Medial Preoptic Area and Behavior
- Hypothalamus and Behavior
8 comments
this kinda explains the whole ‘baby brain’ thing. very interesting to see it has a scientific basis.
I wonder if these findings could be used for medical applications. Could help with postpartum depression maybe?
Its always been said that a woman changes when she becomes a mother. Now we have science to back it up, how cool is that!
Really complex but fascinating. The hypothalamus, neurons, estrogen and progesterone—its a lot to take in but its awesome.
Science never fails to amaze! Who would have thought the brain’s preparing for motherhood just like the body? Hormones are crazy powerful.
Do you think the same changes happen in humans? the article hints at it but I’m really curious if theres more studies on this.
Makes me think about parenting in a whole new light. It’s not just an emotional or social role, but a neurological one too. Mind = blown.
Wow, this is groundbreaking. It’s amazing how pregnancy hormones can actually rewire the brain. Never thought of motherhood from a neurological perspective.