The Null Device
Posts matching tags 'neurochemistry'
2011/3/24
Scientists in China have found that mice bred to not be receptive to serotonin have no sexual preferences for either sex:
When presented with a choice of partners, they showed no overall preference for either males or females. When just a male was introduced into the cage, the modified males were far more likely to mount the male and emit a "mating call" normally given off when encountering females than unmodified males were.
However, a preference for females could be "restored" by injecting serotonin into the brain.The researchers have cautioned against drawing conclusions about human sexuality from the result.
The lazy takeaway from this, as seen in news sites, is that serotonin affects sexual orientation, with the suggestion that low serotonin might be the secret to the inexplicable condition known as homosexuality. I'm wondering whether a more plausible conclusion is that, with sexual selection being about competition amongst fit individuals, a prerequisite for having an active sexual preference is passing an internal test of subjective fitness, i.e., being aware that one has sufficiently high status to be picky. In other words, mice without functioning serotonin receptors perceive themselves as losers who will take anything that's warm and regard it, being more than they're entitled to, as a win.
2003/2/10
As Interflora/Hallmark Relationship Tax Payment Day approaches, an interesting article about how good sex is neurochemically indistinguishable from being in love. The thing that does the magic is a neurochemical called oxytocin, which is released during orgasm and triggers the bonding behaviours in the human brain. So the more sex you have, the more oxytocin you have in your brain, and the more "in-love" you feel. Which can be somewhat problematic if you're not suited to each other outside of the bedroom.
(Yes, it's that time of year. Remind me to keep up the tradition and post some links about how (1) being "in love" is biologically indistinguishable from (a) shooting up heroin, or (b) obsessive-compulsive disorder, (2) the sexual marketplace is not the positive, life-affirming thing it's represented as but rather a brutal, atavistic and ugly form of capitalism-red-in-tooth-and-claw, and (3) it's all a con to take your money and prop up florists, trinket-manufacturing sweatshops and the DeBeers diamond monopoly, and so on.)