A whiff of love

It was end of August 1984, Pondicherry. My wife was in the hospital, about to deliver our first child. The doctor asked me to go get some Oxytocin injection.

I knew that Oxytocin was a small piece of protein made in hypothalamus of the brain and secreted by the pituitary. It induces uterine contractions. Thank god it is not a caesarian, I thought, while running around to look for a chemist's shop, early in the morning.

It is not that I did not have any misgivings. I had read somewhere that it elicited maternal behaviour in virgin female rats [Oxytocin induces maternal behavior in virgin female rats. Science 216, 648–650 (1982)]. Will she become extra maternal because of the Oxytocin injection? Or would the external input of oxytocin shut off the internal production and release, as it happens with the opiate medicines? I wondered while going back to the hospital with Oxytocin in my pocket.

Later, in the 90's, I saw a large number of papers on Oxytocin and the coordinated role that it plays with Vasopressin and other hormones. How prairie voles with higher oxytocin had high affinity pair bonding and lived in monogamy while those with less are rather promiscuous and so on. Nature, the British multidisciplinary journal suggested that it may aid in establishing monogamy. And recently, there were a spate of newspaper articles touting Oxytocin as the love hormone. As befitting the Shakesperean fantasy of a love potion that inhaled as a nasal spray, creating bonding and love...

And then there are scientific papers that claim that nasal spray is a good antidote for anxiety. Pyar huan to darna kya?

The  spray allowed quite a large amount of experimentation in the last few years. Creating trust, generosity, a sense of group identity (PNAS vol. 108 in 2011),.... it was even called a social hormone in the media. Its use in autism was mooted soon.

I thought I should try it. Perhaps I am not very social because of low oxytocin?

But the funny thing is - oxytocin when given as an injection is removed from the blood rather quickly, in a matter of minutes. But this nasal spray continues to act for some 3-4 hours. Why?

I checked. Oxytocin does not cross the blood brain barrier. So the action due to secretion from pituitary is quite transient and only in organs except the brain. Thus perhaps as an aid to child birth, the hormone does not have long lasting effects.

However, oxytocin is supplied to other parts of the brain directly from hypothalamus - even to neurons in the cortex of the brain. So - are there oxytocin channels in the vomeronasal region that these nasal sprays go through, in order to impact on cognition and behaviour?

I would not go hunting for that nasal spray yet. Because there are some other studies that do not really show the same effects. The problem of non-reproduceability is serious, in science.

Looking for possible reasons for these inconsistent results, I came across a series of papers on the oxytocin receptors. There are oxytocin receptors in the brain, as well as in many other parts of the body. If these receptors are not responsive, there is no point in using either the injections or the spray. Like in Diabetes Type 2, where there is insulin circulating in blood, but the person is still diabetic, since insulin can't act without functional insulin receptors...

What is even more interesting is that these receptors are under epigenetic control. Meaning, that you may be born with some predilection for receptivity to oxytocin, but because of your life experiences, these receptors may be made in larger or smaller quantities and perhaps with lesser or greater sensitivity. Social and cultural upbringing can have an impact on how responsive one is, to the nasal spray of Oxytocin.

Still, I for one, would not have minded experimenting with it. I don't seem to notice social cues that fall like a ton of bricks on people around me. I am like a monstrous bull in the proverbial china shop when it comes to social niceties.

The perception of social cues from sounds, facial expressions are increased with Oxytocin. In a recent report in Nature (15th April 2015) scientists claim that these skills are lateralised - to the left hemisphere, like in the case of language. I am terrible in small talk and weak in language that leads to social bonding. But my wife is a person with large variety of social bonds. She is highly perceptive of other people's pains and is kind, considerate and nourishing in her relationships. So external Oxytocin does not seem to have had any consequences, neither for my wife nor my son. I am still human since I breath in the love that they spread around them.

Do people emit Oxytocin?