UC Irvine researchers have asserted the existence of differential wiring in the brains of men and women, impacting perception and reaction. A cluster of neurons processing input such as fear and aggression links to separate cognitive functions.
In men, the cluster integrates with brain regions connected to responsiveness to external stimuli, such as the visual cortex and an area that coordinates motor actions.
In women, the neurons communicates with brain regions linked to internal regulators, such as the insular cortex and hypothalamus. These areas tune in to and regulate women's hormones, heart rate, blood pressure, digestion and respiration.
"Throughout evolution, women have had to deal with a number of internal stressors, such as childbirth, that men haven't had to experience," said study co-author Larry Cahill of the University of California Irvine. "What is fascinating about this is the brain seems to have evolved to be in tune with those different stressors."
The finding, published in the recent issue of the journal NeuroImage, could help researchers learn more about sex-related differences in anxiety, autism, depression, irritable bowel syndrome, phobias and post-traumatic stress disorder.
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The scans also showed that men's and women's amygdalas are polar opposites in terms of connections with other parts of the brain. In men, the right amygdala is more active and shows more connections with other brain regions. In women, the same is true of the left amygdala.
Scientists still have to find out if one's sex also affects the wiring of other regions of the brain. It could be that while men and women have basically the same hardware, it's the software instructions and how they are put to use that makes the sexes seem different.