The hormone oxytocin, commonly known as the "love hormone," may enhance the pleasure of social interactions by stimulating the production of marijuana-like chemicals in the brain, a U.S. study says.
The study conducted by a team of researchers in University of California provided the first link between oxytocin and anandamide - which is also known as the "bliss molecule" due to its capability of activating cannabinoid receptors in neurons to intensify happiness and motivation, in a manner similar to THC in marijuana.
UCI's Daniele Piomelle and his team studied a group of mice that had been either isolated or allowed to interact, and measured the levels of anandamide stimulated in the brain. These marijuana-like neurotransmitters are among a class of naturally occurring chemicals in the body known as endocannabinoids that bind to neuron receptors similar to THC.
The researchers found that there was an increase production of anandamide in the brain when the mice were allowed to make social interaction. When the cannabinoid receptors were blocked, the pleasure of socialization disappeared.
The association between anandamide and oxytocin was also investigated having known that the latter promotes social contact. When the researchers stimulated neurons that generate oxytocin, they noticed an increase in anandamide production in the nucleus accumbens. Moreover, they found that blocking anandamide's effects also blocked the pro-social effects of oxytocin, suggesting that the hormone reinforced social pleasure.
Their findings also showed that mice treated with a drug that inhibits the degradation of anandamide behaved as though they enjoyed spending time with their cage mates more than those treated with a placebo.
"Our findings open the exciting possibility that drugs that block the degradation of anandamide, which are currently being tested for various anxiety disorders, could give a boost to the brain's own oxytocin and help people with autism socialize more," says Piomelli, also the founding director of the Drug Discovery & Development Department at the Italian Institute of Technology, in a press release.
Well, oxytocin can make people feel more extroverted, as revealed by a previous study in 2011.
At present, clinical researchers are investigating it as a possible treatment for the symptoms of autism. However, the main deterrent for such research is the fact that the hormone is difficult to deliver to the human brain.
The study appears in the online journal Proceedings of the National Academy of Sciences.