According to article published in the Proceedings of the National Academy of Sciences, growth hormone (GH) is naturally produced in the human brain.
The involved researchers found that the growth hormone is produced within a structure deep inside the brain known as hippocampus, which is involved in emotion and memory. It was also found that the level of growth hormone is more in women as compared to men, and more in adults.
This study has implications for menopausal women who have been treated with estrogen replacement therapy and athletes who are taking growth hormone and anabolic steroids with an aim to increase muscle mass.
From News-Medical.Net:
The scientists suspect that reasoning and mood may also be affected by these differences in the amount of growth hormone in the brain.
“Growth hormone has been associated with growth of muscles and bones, and the production of it was believed to lie mainly in the pituitary gland,” said co-author Ken S. Kosik, co-director of the Neuroscience Research Center at the University of California, Santa Barbara. “No one had thought too much about what growth hormone might be doing in the brain. Hormones in the brain may not be obvious compared to what they are doing in the rest of the body.”
The authors previously found that hippocampal growth hormone increases with learning. The current study shows that the hormone is very different in males versus females.
“Males and females look different, we act different, so of course our brains are different,” said Tracey J. Shors, co-author and a professor of psychology at the Center for Collaborative Neuroscience at Rutgers: the State University of New Jersey. “There are remarkable differences. People used to think of females as a male with hormones. That’s just not the case.”
The authors found that growth hormone in the brain is increased with stress, especially in males. The effect in females depended on how much estrogen they had at the time. “One interesting interpretation of these results is that exposure to a stressful event increases growth hormone expression in males — but the increase in females may be dependent on their levels of estrogen at the time,” said first author Christine P. Donahue. Donahue, formerly a postdoctoral fellow of Ken Kosik, is an instructor in the Department of Neurology at Harvard Medical School.
The authors behind these findings suggested that growth hormone can cause brain growth as it is associated with overall growth of the body and believed that sex differences in these hormones may be somehow involved when it comes to varying levels of GH in men and women.
