Wednesday 22 April 2020

Squeeze me up, Sapolsky

I promised I'd write a bit more about oxytocin and vasopressin; the Squeeze Hormones. In my original piece, I was struck by the fact that the genes for these two neuropeptides are next door to each other  on human chromosome 20. It is a classic example of gene duplication: in non-mammalian vertebrates there is a single gene in that position with some variation among taxa and a few different names - vasotocin, mesotocin, isotocin - to reflect this. Robert Sapolsky in his book Behave devotes quite a few of then 700 (!) pages to these short proteins and their receptors. <duh!>, me. If I'd thought about it for 45 seconds I would I realised that it takes two to tango. Hormones are at nothing - just whoooshing round the circulatory system - until they dock with their receptor; THEN things kick off inside the cells whose receptor is thus jangled.

It seems that a number of different genetic variants of OXTR, the oxytocin receptor are present in the population of normal adults and researchers are beginning to tackle how, if at all, these changes impact the health and happiness of those who have them on board. They may drive:
If these funded research topics make you think hmmmm IgNobel awards, then you are not alone. But then the whole point of IgNobels is first they make you laugh, then they make you think. That last one is interesting because it may be an example of co-evolution and explain the, frankly peculiar, affiliative relationship between humans and dogs. When your pooch looks all big-👁y👁s at you there is a rush of oxytocin at both ends of the stare. Somehow, both species have extended the limits of Us to the exclusion of Them. I see now (I tell ya b'ys, I've forgotten more blobbery than I can remember writing) that I covered this puppy luv phenomenon 5 years ago.

Within this our own species, oxytocin's effects are not indiscriminate. The standard research protocol in neuropeptide research is to spritz a solution of oxytocin up the punter's nose and then test them for implicit racism, or recognising and remembering the emotional state shown in a series of photographs. It turns out that a shot of oxytocin makes you bond more strongly with Us [family first, but also neighbours / people with the same tan as you] but brings out the worst in your assessment of black people [or travellers, if you're Irish]. In that sense oxytocin [and testosterone in a different but parallel tale] makes you more so of whatever your natural proclivities are. Some of your ways of being and interacting with others are genetic (OXTR variants?) but others are learned and that's a whole of can of nature / nurture worms. Sapoxytocsky  in the classroom and bloke-talking with Joe Rogan.

As a black and white sorta bloke, I've had vasopressin nailed as having two quite different but weirdly related functions: 1) it causes smooth muscles of the arteries to contract 2) wearing its anti-diuretic hormone ADH cape it slows water loss through the kidneys. Both of these serve to drive up blood-pressure and ensure that your brain gets enough oxygen to work under a wide variety of [adverse?] circumstances. But that's not all! vasopressin, like its sister oxytocin, also modulates behaviour. In fine, it increases human risky cooperative behavior and probably a rake of other peculiar attributes of the human condition. SADHpolsky in the classroom; where inter alia he kites the idea that autism runs in families that have a particular vasopressin receptor variant which, in other species, correlates with low levels of attachment. As Sapolsky says - it has to be more complex than that; and it is. But ya gotta put a few ideas Out There if we're ever going to shake up our complacency and make some progress in science.

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