Male and female brains react differently to stress

Offering new evidence to show that male and female brains are wired differently, new research has found that a brain region involved with stress and keeping heart rate and blood pressure high work differently in men and women.

While measuring brain activity with magnetic resonance imaging (MRI) during blood pressure trials, the researchers found that men and women had opposite responses in the right front of the insular cortex, a part of the brain integral to the experience of emotions, blood pressure control and self-awareness.

The insular cortex has five main parts called gyri serving different roles. 

The researchers found that the blood pressure response in the front right gyrus showed an opposite pattern in men and women, with men showing a greater right-sided activation in the area while the women showed a lower response.

"This is such a critical brain area and we hadn't expected to find such strong differences between men and women's brains," said the study's lead author Paul Macey from University of California, Los Angeles.

This region, the front-right insula, is involved with stress and keeping heart rate and blood pressure high. 

"It's possible the women had already activated this region because of psychological stress, so that when they did the physical test in the study, the brain region could not activate any more. However, it's also possible that this region is wired differently in men and women," Macey noted.

The study was published in the journal Frontiers in Neurology.

"We have always thought that the 'normal' pattern was for this right-front insula region to activate more than other areas, during a task that raises blood pressure," added Macey.

"However, since most earlier studies were in men or male animals, it looks like this 'normal' response was only in men. The healthy response in women seems to be a lower right-sided activation," he noted.

"We believe that differences in the structure and function of the insula in men and women might contribute to different clinical symptoms in some medical disorders," Macey said.