Når kjemien stemmer

Forskere har funnet at hormonet oxytosin, som blant er assosiert med melkeutdriving og morsatferd, påvirker hvor mye mennesker stoler på andre. De har gitt nesespray med oxytosin eller placebo i eksperimenter der folk får velge om de skal stole på at andre kan investere pengene deres riktig.

Gruppen som fikk oxytosinspray stolte mer på at investorene skulle forvalte pengene deres riktig, selv om de hadde blitt lurt. Les mer her og her.

A nasal spray which increases our trust for strangers is showing promise as a treatment for social phobia, say scientists from Zurich University. They found that people who inhaled the "love hormone" oxytocin continued to trust strangers with their money - even after they were betrayed.

Brain scans showed the hormone lowered activity in the amygdala - a region which is overactive in social phobics. Nicknamed the "cuddle chemical", oxytocin is a naturally produced hormone, which has been shown to play a role in social relations, maternal bonding, and also in sex.

Lead researcher Dr Thomas Baumgartner said: "We now know for the first time that exactly is going on in the brain when oxytocin increases trust. "We found that oxytocin has a very specific effect in social situations. It seems to diminish our fears. Based on our results, we can now conclude that a lack of oxytocin is at least one of the causes for the fear experienced by social phobics. We hope and indeed we expect that we can improve their sociability by administering oxytocin."

Previous studies have shown that participants in "trust games" took greater risks with their money after inhaling the hormone via a nasal spray. During the games, the players' brains were scanned using functional magnetic resonance imaging (fMRI). The researchers found that oxytocin reduced activity in two regions which act as natural "defence barriers". They are the amygdala, which processes fear and danger, and an area of the striatum, which helps to guide future behaviour, based on reward feedback. The amygdala has been found to be extremely active in the brains of sufferers of social phobia.

Her finner du artikkelen i Nature.

Oxytosin er syntetisert i alle fall til sau og gris (ja, også menneske da!), så vidt jeg vet. Hormonet brukes først og fremst til å fremkalle rier og å få igang melkeutdrivingen. Er oxytosin artsspesifikk eller kan den brukes på tvers av alle pattedyr? Noen veterinærer som har oversikt over det?