Oxytocin is often known as the love hormone because levels in your body increase when you’re sexually aroused or fall in love. But less well known, it plays an important role in learning and memory.
So, it’s no surprise that a groundbreaking new study is paving the way for innovative treatments using oxytocin to manage cognitive decline and dementia.
Oxytocin is produced in the hypothalamus, a key learning and memory center of the brain. Higher levels create empathy, trust, and social bonds. This hormone also regulates your response to stress, lowering the stress hormone cortisol, reducing blood pressure, and acting against inflammation. Not surprisingly, low levels of oxytocin are found in people suffering with depression. The research is clear that oxytocin has wide roles in both physical and mental health, especially when it comes to memory.
May Reverse Alzheimer’s Damage
Scientists in Japan have recently focused their attention on the role of oxytocin in brain health and have published four papers to date. In one of the research studies they were able to reverse some of the damage caused by amyloid brain plaques in an animal model of Alzheimer's, suggesting that oxytocin could be a new treatment for the disease.
They’ve now followed that breakthrough study with another…
This time they discovered exactly how oxytocin influences memory in mice by studying oxytocin neurons and receptors. These neurons and receptors function differently based on how much oxytocin is available to the brain.
Boosts Long-Term Spatial Memory
The scientists delved into the complex neural pathways and signaling mechanisms activated by oxytocin.
Professor Akiyoshi Saitoh at Tokyo University, who headed the research, explains, saying, “…in this study, we examined the role of endogenous oxytocin in mouse cognitive function. This was done by using pharmacogenetic techniques to specifically activate oxytocin neurons in specific brain regions.
“The cognitive function of mice was then evaluated using the Novel Object Recognition Task (NORT)." In other words, they used a test that mainly evaluates recognition memory in rodents. It reflects the fact that the mice spend more time exploring a new object than one that’s familiar to them.
The scientists activated oxytocin neurons in an area of the rodents’ hypothalamus called the paraventricular hypothalamic nucleus (PVN), a key area for oxytocin production, and then tested them with the task.
They discovered that short-term spatial memory in the mice - which allows them to remember where objects are located - was unaffected. But for the first time a profound change in long-term spatial memory was shown. In other words, oxytocin helps the mice remember better over the long term.
Increases Activity of Key Memory Areas
Another important discovery was that the activation of oxytocin neurons in the PVN increased activity of hypothalamus regions called supramammillary nucleus (SuM) and dentate gyrus. These are both critical memory areas that can be negatively impacted by age and dementia.
The finding that activity in the PVN projects to the SuM to drive recognition memory was so important it needed to be corroborated by another test which confirmed heightened neuron activity.
Finding the neurons responsible for oxytocin’s effect on memory has implications for understanding the role of the hormone in Alzheimer's disease and in modulating recognition memory. In fact, in their paper published in the journal PLOS ONE in November, the research team wrote that “oxytocinergic neuron activity may be involved in each stage of Alzheimer’s disease pathological progression.”
That’s a pretty remarkable statement. Of course, it’s early days. Although there’s only been one human study to date, it showed that Alzheimer’s patients had lower plasma oxytocin concentration compared to healthy individuals. This provides additional preliminary evidence that when it comes to dementia, oxytocin is not just relevant to mice.
The science led researchers to another important conclusion…
Explains The Harm of Social Isolation
The findings also provide an explanation for why loneliness and social isolation are harmful to the brain and increase the risk of dementia, as pointed out by Professor Saitoh.
“There is a widely acknowledged belief that dementia tends to advance more rapidly in settings where individuals experience loneliness or limited social engagement. However, the scientific underpinnings of this phenomenon have remained largely elusive. Our research seeks to elucidate the crucial role of a stimulating environment that activates oxytocin in the brain, potentially mitigating the progression of dementia.”
The findings of the Japanese scientists suggest oxytocin could become a treatment for cognitive decline and dementia in the future. In the meantime, you can boost your own production of oxytocin through exercise, music, – especially singing in a choir - or by giving someone a hug.
