What activity may form new neurons in the brain?

The answer is B, sex.

Researchers at the University of Calgary found that sex triggers the development of new neurons in the smell, or olfactory, center of the brain. Sex increases the production of a hormone called prolactin that prompts stem cells in the brain to produce new neurons in the brain's olfactory bulb or smell center.

Working on mice, the researchers discovered that mating and pregnancy caused surges in prolactin levels and consequently stimulated new neuron production. Artificially introducing prolactin into the blood stream also stimulated production of new neurons for the olfactory bulb. They do not know yet whether the same process works for humans as well, but they do know that sex triggers a surge of prolactin in humans.

So what are the implications of this discovery? Well, now that we know that prolactin has the potential for generating new brain cells, researchers could try to find a way to send new neurons to parts of the brain other than the olfactory bulb, so as to boost the brain's self-repair process. This may eventually help to repair damage done by stroke or diseases such as Parkinson's or Alzheimer's.

Resources:

Read more about the University of Calgary study at the Canadian Broadcasting Corp. Web site.