A team from Sue Carter's lab showed that daily doses of oxytocin can prevent the cardiovascular damage caused by loneliness.

Yes, loneliness isn't only psychologically painful. It leads to chronic elevated levels of cortisol that damage the heart and raise blood pressure.

In a study announced today, Angela J. Grippo, C. Sue Carter and Stephen W. Porges, all with the Department of Psychiatry and Brain-Body Center at University of Illinois at Chicago, isolated adult female prairie voles for four weeks; the control group of females was housed with a female sibling.

These highly social beasts usually live within the family unit until they mate. Once they mate, they form their own monogamous family unit (although they may copulate occasionally with voles other than their mates). Isolation is really hard on these animals, just as it is on humans. Prairie voles also have similar patterns of receptors for oxytocin, vasopressin and dopamine to humans; it's likely that they provide a good model for human social behavior.

The researchers gave the voles either saline solution or oxytocin daily for the last two weeks. After the four-week period, each animal was put in the stressful situation of meeting an unfamiliar vole.

For the isolated voles, oxytocin improved the general regulation of the heart and lowered their stress response to the unfamiliar animal; the control group didn't show responses to the external oxytocin.

According to the researchers,

These findings suggest that oxytocin can prevent damaging cardiac changes in adult female prairie voles exposed to social isolation.

Before you run for your oxytocin inhaler, let's consider what this means. What they did in this study was to replace the oxytocin that would have been naturally generated by the voles as they huddled with their sisters. (Huddling is the non-anthropomorphic term researchers use for cuddling-type behavior.) The isolated voles couldn't cuddle; an exogenous dose of oxytocin therefore was needed to keep their cortisol down and deactivate the sympathetic nervous system.

If you were an astronaut, or in an arctic research lab, it might be a great idea to take oxytocin. But our bodies are designed to do this naturally. Nurture your own oxytocin response. If people are too much, petting a dog is a great way to get the oxytocin flowing.

See also: My Dog Really Loves Me, Inside the Loneliness Lab