[url]www.canada.com/news/story.as...62-44C3A2DE8366 [/url]

Hormone stimulates new cells

Mario Toneguzzi
Calgary Herald


Friday, January 03, 2003

CREDIT: Lorraine Hjalte, Calgary Herald

Doctor has Sex on the Brain: Dr. Samuel Weiss of the University of Calgary and a team of researchers have discovered that sex and pregnancy produce a hormone that generates new brain cells.



A hormone that generates new brain cells after sex could be the key to stroke recovery, according to groundbreaking research by University of Calgary scientists.

Dr. Samuel Weiss, of the U of C's faculty of medicine, led a team of researchers studying stem cells, pregnancy hormones and brain repair. They discovered the naturally occurring hormone prolactin -- which surges after sex and during pregnancy -- prompts stem cells in the brain to produce new neurons in the brain.

Weiss said scientists are testing to determine if the hormone can be given immediately following a stroke.

"This is an important area we're going to research in the future," said Weiss at a news conference Thursday in Calgary.

Weiss is now collaborating with Dr. Bryan Kolb of the University of Lethbridge, with the support of the Canadian Stroke Network of the Networks of Excellence Program.

"We have exciting preliminary data suggesting that the new stem cell-generated brain cells can be redirected to parts of the rodent brain that are damaged after a stroke, and this results in a partial improvement of the animal's ability to move its limbs," said Weiss.

"Because prolactin is a natural-occurring hormone that is part of the intrinsic process of stimulating new brain cell production, and because it can be added directly into the bloodstream to produce the brain effect, we are preparing to test how it might help stroke recovery."

This new data follows on a team of researchers' work, led by Weiss, which gathered scientific proof that, in female mice, prolactin stimulates the production of new brain cells in a part of the brain responsible for the sense of smell, during the early stages of pregnancy and shortly after delivery.

The research will be published today in the journal Science.

Weiss is the senior author of the study. The work was a collaboration between his laboratory and that of James Cross, also part of the genes and development research group at the University of Calgary.

The researchers were building on a discovery Weiss reported about a decade ago, that the brains of adult mice contain stem cells which are the body's building blocks.

Stem cells have the capacity to turn into any type of cell.

Later it was shown that the adult human brain contains stems cells, as well.

Those findings were considered monumental, because it had long been believed that the brain cannot generate new cells to replace or repair those lost to injury.

But the actual function and regulation of these adult brain stem cells remained elusive -- until now.

The production of new neurons by the stem cells was discovered to be stimulated in the forebrain of female mice during pregnancy because of the hormone prolactin.

Researchers then determined that the new neurons migrate to the olfactory bulb where they are necessary for the adult mouse to be able to remember new odours and to distinguish them from other similar odours.

The olfactory function is critical for a female mouse to be able to recognize and take care of her offspring.

Weiss said this behaviour is present "in every animal we've studied today, from fruit flies to primates."

But researchers also found that new brain cell growth occurred even in females that mate with sterile males -- suggesting that pregnancy alone is not the catalyst to unleashing prolactin, but the act of sex serves as the trigger.

Researchers also found that if prolactin was given to male mice, they also showed an increased production of new brain cells.

The discovery that new brain cell generation can be stimulated in a certain area of the brain led researchers to the exploration of re-mapping the migratory route of these cells to serve in the treatment of strokes.


[sex]

No wonder I'm an idiot.

Uuuumm, huh?[:E]

So where's my Nobel prize?

LT ought to be one mentally challenged bastard! BTW I [i]used[/i] to be fairly intelligent. Does wacking off count?

Well, that explains why I feel like I've been firing on all cylinders lately.

Righteous!

If that's true then how come I can't figure out how to make these blisters go away?

oh dear god!  i knew i was a genious for some reason!

This would explain why I often felt like a genius in the past - but presently feel like I should be on the short bus..................

Does this work if you...um...make yourself smarter?

LOL! Maybe you should change your sigline to "Rubbin' one out"! [:D]