The researchers -- from three institutions –?found that growth hormone is produced within the hippocampus, a structure deep inside the brain that is involved in memory and emotion.
The scientists also found that more growth hormone is produced in females than in males, and more in adults. More growth hormone was also produced in response to estrogen. The study has implications for menopausal women using estrogen replacement therapy and for athletes taking growth hormone and anabolic steroids to increase muscle mass.
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, especia
Source:University of California - Santa Barbara