Reproductive Hormones as Our Brain’s Bodyguards
By Tyler Raikar | Contributing Author
Dr. Meharvan Singh | Credibility Partner
When you think of the word “hormones”, I want you to think of what first comes to mind. Chances are, you thought along the lines of “mood”, “personality changes”, “stress”, or maybe “sexual function”.
Now let’s take it one step further– when one thinks of the specific roles of reproductive hormones, such as progesterone, estrogen, or luteinizing hormone (LH), we tend to blend the roles of these individual hormones together and associate them with “females” and “periods”.
These may be the only roles of gonadal hormones that you’re aware of– social media may flood feeds with limited information, or even misinformation.
But now that you’re taking the time to read this, it means that you care to know more about the power of hormones. Being aware of your hormones’ full functionality is key to understanding how your body operates. Their fluctuations might solve the mystery of why some days you may feel “off”.
Hormones serve far more purposes in our bodies than commonly known. Think of hormones as our bodies’ leaders, instructed to delegate tasks to get work done. These tasks may include controlling our metabolism, our electrolyte balance, or our body temperatures. With there being over 50 identified hormones flowing through our bodies, each individual one serves a nuanced role that allows our organs to work harmoniously amongst another.
Alluding back to reproductive hormones, their roles in the body, both male and female, are rather fascinating. In fact, recent research reveals how amazing they are as healers in our nervous system. That’s right– reproductive hormones are not just for reproduction, ironically.
To dive deeper into what this means, let’s consider the hormone of progesterone. Reproductively, progesterone is responsible for preparing the female body’s uterus for pregnancy. It triggers a physiological response in the body for thickening the tissue of the endometrium, the inner lining of the uterus, to support menstruation and the early stages of pregnancy.
Now, here’s where things get interesting: in studies conducted by Dr. Meharvan Singh et al., they found that progesterone is protective against neurodegenerative diseases. What exactly does that entail? Let’s break it down.
Progesterone as a Neuroprotective Agent
Progesterone is produced in the gonads, which gears its reproductive function. However, it is also produced in the central and peripheral nervous system, which means it also functions as something called a neurosteroid, a class of steroid hormones that are synthesized in the brain. Neurosteroids are key players in reducing stress and anxiety, regulating mood, and embodying anti-seizure activity.
The specific role of progesterone as a neurosteroid, then, is its ability to protect brain cells from brain injuries and neurodegenerative diseases. This may include Alzheimer’s, traumatic brain injuries (TBIs), strokes, Huntington’s disease, and Parkinson’s disease.
One of the key mechanisms that these diseases have in common is glutamate-induced excitotoxicity – in other words, when a neurotransmitter called glutamate is excessively stimulated in the brain, it may cause the death of neurons. This imbalance of glutamate is caused by many factors, such as its overproduction or impaired clearance, but this differs from case to case.
Now here’s the exciting news– in several recent experimental studies done with rat models, progesterone was found to reduce the damage caused by dysregulated glutamate by attenuating excitotoxicity injury. In other words, it supported the survival of neurons!
Research continues to explore progesterone's protective properties. For example, Dr. Singh and his team reviewed that it may be a promising treatment plan for TBIs– when animal models with recent TBIs were administered progesterone, they found that their cerebral edema (swelling of the brain) reduced for up to 24 hours after the injury.
What’s amazing about progesterone is its multifaceted function in the central nervous system: not only is it protective against glutamate excitotoxicity, but also against glucose depletion and iron toxicity in the brain. This list is not exhaustive, and it applies to men and women.
The Roles of Other Gonadal Hormones
Given that progesterone has a profound role in our nervous system, it’s only natural to wonder whether other reproductive hormones also influence the brain — and you’d be right to think so!
What remains a critical future direction in the realm of this research is to differentiate the effects of biological sex from reproductive hormones on the CNS. Our limited understanding of how sex and hormones affect the brain may be what is hindering the development of effective interventions, specifically for aging women, who experience a higher burden from neurodegenerative diseases than men.
