Researching oxytocin takes you in one of two directions.

Explaining its chemistry is not something that can be done easily with plain language. Greek tells you that it means "quick birth." This tells you nothing.

Oxytocin is a nonapeptide. Peptides are combinations of amino acids. "nona" is nine — Oxytocin is a combination of nine amino acids. If you are a neurologist, you probably wrote down and memorized a mnemonic expressing the order of these acids to better reproduce them on an exam. You may have associated them with childbirth, with love, but having experienced neither the analogy became lifeless. When in love one has little time for mnemonics: oxytocin is bad for memory.

Oxytocin's chemical formula is C43H66N12O12S2. 1 You know that hydrogen combines with oxygen, producing water. You know that sulfur generates the stink in fertilizers. Diamonds and coal are made of carbon. Three-quarters of the air is nitrogen. You know that atoms quantify existence, but something is lost in the combination that produces oxytocin. The mathematics of chemistry express the universe in a self-referential language that works perfectly, and only, for those looking to understand the universe in terms of numbers.

The other direction in which one is taken while learning about oxytocin is more emotionally ambitious but equally dead. Oxytocin is the "cuddling chemical." Oxytocin makes you feel empathy. Sex and childbirth both involve lots of oxytocin. Cupid dips his arrows in oxytocin — how quaint. It is very easy to absorb information without learning.




I bought a few pounds of London broil today at the market for the first time in months. Oil prices are reflected in food: this cut, while large, was significantly more expensive than it would have been in January. Still cheap as meat goes.

Muscle tissue contains nerves. Oxytocin sometimes doubles as a neurotransmitter and occurs in mammals, like cattle. Cows lactate, their mammary glands emboldened by oxytocin. That their milk is everywhere numbs us to the meaning of this. "Lactate" is a term we save for mothers. Everyday, mothers pour their own milk into the sink.

I'll eat this steak tonight — rare. The proper term would probably be "blue." This will be an act of penance. The romantic in me likes to think that, having spared the interior much of the heat responsible for chemical breakdown, some molecules of the cuddling chemical will be absorbed into my own body. I know however that the resulting pangs of empathy will originate completely in my own nerves. This does not matter.



 

Social relations between humans critically depend on our affective experiences of others. Oxytocin enhances prosocial behavior, but its effect on humans' affective experience of others is not known. We tested whether oxytocin influences affective ratings, and underlying brain activity, of faces that have been aversively conditioned. Using a standard conditioning procedure, we induced differential negative affective ratings in faces exposed to an aversive conditioning compared with nonconditioning manipulation. This differential negative evaluative effect was abolished by treatment with oxytocin, an effect associated with an attenuation of activity in anterior medial temporal and anterior cingulate cortices.
Oxytocin Attenuates Affective Evaluations of Conditioned Faces and Amygdala Activity,2 from The Journal of Neuroscience.



More simply: oxytocin helps you recognize facial cues.

The amygdala is a funny thing. The term 'emotional memory' can be a difficult one to grasp.

Our grandmother spent a long time in Hospice seven years ago. After a bypass, and a stroke, and congestive heart failure, she deteriorated slowly enough so that each weekend was hypothesized to be her last. This happened several times. Doctors marveled at how long she survived. They were apologetic about it.

Not knowing what else to say, other family remarked that as a baby and an invalid one is more or less the same.

My sister gave birth to her first child, a daughter, at the end of May.

I drove to the desert and visited my niece the weekend after she was born. She had a concave mouth and a full head of black hair, even at six days old. She made faces, as babies will.

"She reminds me of Abuela," I said.

My sister, surprised, looked at her husband. "Didn't I say that? At the hospital?"

He nodded.

"It's really weird that you say that," she said. "They say that with reincarnation it's really rare for two lives to coincide one right after the other. I wonder if there's anything to that."

I said, "maybe," thinking about chemistry, and divinity.





Love is not an emotion.

Students who, by their own definition, were deeply in love were put into brain scanners at London's University College. Going on brain activity, their minds did not resemble those of emotional people (say, someone who's angry) — they looked like those of crack addicts.

Did I say love is not an emotion?

Wait until you wake up together for the first time. Wait until the shock of heat, greater than a body at rest can produce, at first touch. When it is so much you are aware of nothing, not even how desperately young people can feel certain things. Imagine that it's amino acids. Remember molecules from middle school. Something is missing.

Love is not an emotion.

An oft-cited example of oxytocin's role in commitment is in two species vole (of all animals) who share, naturally, 99% of their DNA. The short version: the species that produces it stays monogamous. Inject it into rats, animals which mate for the dopamine high, and find that they've adopted the sex habits of doves.

Did I say love is not an emotion?

Wait until she stops calling. I can still feel her before she comes home. A romantic might say that when the oxytocin wears off it's time to move on, but a scientist would remind you of crack addicts. I know her body produces the same warmth it did when I could not bring myself to notice whether the sun was shining. I know it's the same house we built together, the same air, the same California heat that mixed our sweat. The landscaping we coaxed out of irrigation and clay is dying. When she rests her head on my belly there is the same mitochondria, probably still oxytocin, but in her eyes something is missing.

Divinity, answers, are always in what is missing.


1 Wikipedia.
2 Authored by Predrag Petrovic, Raffael Kalisch, Tania Singer, and Raymond J. Dolan; available at http://www.jneurosci.org/cgi/content/abstract/28/26/6607.


Other sources:

University of California, San Francisco. "Hormone Involved in Reproduction May Have Role in the Maintenance of Relationships." http://www.oxytocin.org/oxytoc/.

doyle says re oxytocin: If you ever watch a woman in labor get an oxytocin drip (I think the trade name is Pitocin), watching the uterus just about rip itself apart, well, "quick birth" makes sense.

jessicaj says re oxytocin: I hesitate to contradict doyle but I was induced and it was anything but quick.

 

nb: originally from 2008