A mice study has shown that social support can help minimize some of the worst physical damages to the brain caused by a heart attack.
From cell death to depressive symptoms to regulation of the heart, mice that lived with a partner after a heart attack suffered less damage than did similar mice that were housed alone.
"The results really get at the profound influence that the social environment can have on health after cardiac arrest," said Greg Norman of Ohio State University (OSU).
Mice in the study showed damages to the regulation of their heart rate within 24 hours of cardiac arrest. But those mice that lived with a partner showed significantly less damage, and had more normal control of heart rate variability.
"This is another way that social interaction is able to improve health functioning after a heart attack," said Norman.
For the study, male mice were either housed alone or with a female mouse for two weeks. Mice were implanted with a device, similar to an ECG in humans that transmitted data on heart rate variability and other heart functions.
After two weeks, some of the mice underwent a surgically induced heart attack, while others were placed in a control group that did not undergo cardiac arrest.
The mice that had the heart attack were resuscitated. These mice were then tested 24 hours, three days or seven days after the heart attack on various measures of health.
On nearly every measure, mice that lived with a partner showed less damage after the heart attack than did those that lived alone.
"The only difference in those groups was the living arrangements.
"Something as simple as living with another mouse can cut in half the amount of cell death in the brain as a result of cardiac arrest," Norman said.
In one test, socially housed mice showed less depressive-like symptoms than did mice that lived alone. Mice with a partner spent more time swimming when placed in water, while socially isolated mice spent much more time floating, which is seen as a depressive symptom.
"Cardiac arrest, even among mice in good social conditions, is inducing some depressive-like behaviors," DeVries said.
"But depressive symptoms are more pronounced for mice that lived alone," he added.
The results also showed evidence that socially isolated mice had more activity in the brain associated with the creation of pro-inflammatory chemicals, such as tumor necrosis factor alpha (TNF-a).
The findings were published in the online edition of the Proceedings of the National Academy of Sciences.