love hormone

Introduction

Hello Internet, today’s guest is Oxytocin. Oxytocin is another significant neurotransmitter/hormone which is normally produced in the hypothalamus and released by the posterior pituitary.

It could be categorized among the main happy chemicals like dopamine, serotonin, and endorphins, even though each one of them has a specific impact on happiness (from boosting pleasure to managing anxiety).

Oxytocin was first known for its role in female reproduction, as long as it is released in large amounts during labor and contributes to lactation.¹ Consequently for many years, researchers saw it primarily as a pregnancy hormone.

However, its role is broader than this. Only over the last decades, researchers have focused on what functions Oxytocin might have in the brain. And the discoveries, huh, are spectacular!

The “love hormone”

As we mention in the title, oxytocin is usually called a “love hormone” (or “love drug”). It appears that humans are experiencing high levels of Oxytocin in the first stages of a romantic attachment. Interestingly, those high levels of Oxytocin persisted for at least (!) six months.²

The above observations in combination with the secretion of Oxytocin during sex and orgasm led to the domination of the term “love hormone”.

However, Oxytocin’s role in love attachments is just the tip of the iceberg. Oxytocin contributes to or has starring roles in many other functions of the human brain as well.

The 5 facts you didn’t Know

Fact #1: The sex hormone

The first fact we are going to investigate is the relation of Oxytocin with sex. It appears that the “love hormone” can contribute to causing erection during sexual arousal, in both men and women. Studies have shown that during sexual arousal the levels of Oxytocin in humans are increased.^3–6

Can oxytocin indeed increase the lust for sex? Interestingly, it seems that the answer is yes. Not only it increases the desire for sex but also Oxytocin is raised during, or immediately after, the orgasm or ejaculation.^4,7

It should be also noted that a study shows that anorgasmic women showed lower oxytocin levels than orgasmic ones before and after sexual intercourse.⁸ And, if you think about it, this is something that, in a way, seals the previously mentioned results!

Fact #2: Social Bonding, Love, and Trust

To understand how oxytocin is related to some complex social behaviors such as bonding, trust, and love, we will mobilize the love life of some (!) voles. Yes, you read correctly.

In the woodlands of Europe and Asia can someone meet one of the only 3% of mammal species that appear to form monogamous relationships, the prairie vole. It will take 24 hours of tremendous effort for them to mate but once they do it, they will spend the rest of their lives together.³ It sounds like a Disney novel, right? And yet, it’s true.

Moving now from Disney’s novel to “American Pie 3”, we meet another vole, the montane vole. Even though those two kinds of vole are 99% genetically alike, the montane vole has exactly the opposite love habits. It has no interest in partnership beyond one–night–stand sex! This major difference is just because of different endocrine functions.

But what actually does happen here? Well, when prairie voles have sex, Oxytocin, and vasopressin are released. Interestingly if the release of those two hormones is blocked, then prairie voles act exactly as their montane cousins!³

Consequently, Oxytocin has a starring role in love, and more generally in every social bonding (from attachment security, mating, paternal behavior, and motherhood). It appears that the key role of Oxytocin is that contributes to building trust between people.

Consider this, research, which contained a money game, showed that people’s trust, even in a stranger, was raised with a nasal spray of Oxytocin. Somebody can even invest more money if he was given intranasal Oxytocin 50 minutes before the decision.⁹

Fact #3: Social Behavior

The recognition of individuals and having the proper response to them is a supreme ability we, humans, take for granted. Imagine a world where life is the same as now and you can have the exact same behaviors with people BUT you can’t recognize any person. You will have all these feelings of admiration, liking, anger, love, etc. but you will not remember to who; or maybe you won’t generate all these feelings at all.

Well, thanks to our complex minds we can recognize a conspecific and figure out the proper reaction to that individual, leading to the formation of a ‘social memory’ of people and displaying of appropriate behaviors within a social group. This is where Oxytocin shows up since it is involved in forming social memory and the ability of social recognition.¹⁰

The social story, though, didn’t come to an end.

What comes after social memory?

A bond; A social bond! (For the few 😁).

As you could imagine, Oxytocin plays a crucial role in the formation of different kinds of affiliative bonds. It appears that oxytocin is greatly implicated in a broad spectrum of bond formation. From parental behavior to friendship bonds to bonds with pups, and, of course, to sexual affiliations.¹⁰

Fact #4: Non-Social Behavior

Believe it or not, Oxytocin contributes to other behaviors except the social ones we have already mentioned. One of these is its role in stress, anxiety, and depression.

Apart from the association of Oxytocin’s imbalances with both anxiety and depression cases, it also seems to have an anxiolytic behavioral profile. Since both physiological and psychological stressors increase Oxytocin release in a few key brain regions which leads to dampening of the release of stress hormones. ¹⁰

And voila, the magnificent catchphrase: “Love Decreases Stress”.

And what is Oxytocin’s role in cognition ability? Well, it seems that the news is not as good as the latter. Although the evidence is not enough to give a confident conclusion; still, research shows that Oxytocin can affect learning and memory.

For instance, the administration of Oxytocin significantly decreases memory, accuracy, and decisiveness. It also shows deficits in learning processes.^10,11

Fact #5: Feeding, Grooming, and (!) Pain Perception

Feeding, grooming, and pain perception. What affiliations might have those with Oxytocin levels? Well, it seems that they have, and they are very interesting. I am getting started with the one that impressed me, and this is pain perception.

Interestingly, it appears that Oxytocin reduces pain perception. What does this mean? It means that when someone is exposed to a painful event, either physical or physiological, Oxytocin plays a significant role in the pain one perceives.^12,13

When Oxytocin levels are high, one will “experience” less pain! Okay, someone might say that the pain is the same; what is, actually, changing is the perception of it.

And here I am for another great catchphrase: “Love Reduces Pain”. How does it sound?

Moving forward to grooming I think that everyone who has read this article will guess that Oxytocin and grooming have a positive correlation. And this is true.

Research on beloved rodents has shown that the administration of Oxytocin enhances grooming activity in both males and females.¹⁴

Finally, feeding seems to be the more complex one of the three. This is because a lot of factors might contribute to this; just so to mention one, remember the dopamine reward system. However, someone can claim that generally, Oxytocin suppresses food intake.¹⁰

Takeaway

What a magnificent molecule Oxytocin is, huh? We just saw that the known “love hormone” plays a significant role in severe sections of our life.

This hormone, when first discovered, was connected only with female reproduction; it evolves into the neurotransmitter that most people recognize for its affiliations with love; and now it appears to be a great facilitator for life. Consider the broad spectrum of its role, from its contribution to sex and social bonding to depression and pain perception. Wow!

Reaching the end, I could say that this article was so lovely. Thanks for reading, stay informed and give love a chance.

References

1. Palareti G, Legnani C, Cosmi B, et al. Comparison between Different D-Dimer Cutoff Values to Assess the Individual Risk of Recurrent Venous Thromboembolism: Analysis of Results Obtained in the DULCIS Study.
2. Schneiderman I, Zagory-Sharon O, Leckman JF, Feldman R. Oxytocin during the initial stages of romantic attachment: Relations to couples’ interactive reciprocity.
3. Magon N, Kalra S. The orgasmic history of oxytocin: Love, lust, and labor.
4. Cera N, Vargas-Cáceres S, Oliveira C, et al. How Relevant is the Systemic Oxytocin Concentration for Human Sexual Behavior? A Systematic Review.
5. Ückert S, Becker AJ, Ness BO, et al. Oxytocin plasma levels in the systemic and cavernous blood of healthy males during different penile conditions.
6. Dickenson JA, Alley J, Diamond LM. Subjective and oxytocinergic responses to mindfulness are associated with subjective and oxytocinergic responses to sexual arousal.
7. Carmichael MS, Humbert R, Dixen J, Palmisano G, Greenleaf W, Davidson JM. Plasma oxytocin increases in the human sexual response.
8. Caruso S, Mauro D, Scalia G, Palermo CI, Rapisarda AMC, Cianci A. Oxytocin plasma levels in orgasmic and anorgasmic women.
9. Kosfeld M, Heinrichs M, Zak PJ, Fischbacher U, Fehr E. Oxytocin increases trust in humans.
10. Lee HJ, Macbeth AH, Pagani JH, Scott Young W. Oxytocin: The great facilitator of life.
11. Ferrier BM, Kennett DJ, Devlin MC. Influence of oxytocin on human memory processes.
12. Yang J, Yang Y, Chen JM, Liu WY, Wang CH, Lin BC. Effect of oxytocin on acupuncture analgesia in the rat.
13. Yang J, Yang Y, Chen JM, Liu WY, Wang CH, Lin BC. Central oxytocin enhances antinociception in the rat.
14. Drago F, Pedersen CA, Caldwell JD, Prange AJ. Oxytocin Potently Enhances Novelty-Induced Grooming Behavior in the Rat.