A newly-discovered protein in the semen of all mammals -including humans – prompts females to ovulate through a direct effect on the brain.
Surprisingly, it’s the same molecule that regulates the growth, maintenance, and survival of nerve cells – nerve growth factor (NGF) which is found primarily in nerve cells throughout the body.
The scientists, though, say that large amounts of the protein are produced by the accessory sex glands that contribute seminal fluid to semen.
“To our surprise, it turns out they are the same molecule,” says Gregg Adams of the University of Saskatchewan. “Even more surprising is that the effects of NGF in the female were not recognized earlier, since it’s so abundant in seminal plasma.”
NGF in the semen acts as a hormonal signal, working through the hypothalamus of the female brain and the pituitary gland. This triggers the release of other hormones that signal the ovaries to release an egg or eggs.