Cut out the (estrogen) middleman

Dec 08, 2009

Estrogen seems to act like a middleman in its positive effect on the brain, raising the possibility that future drugs may bypass the carcinogenic hormone altogether while reaping its benefits.

A split-personality chemical, is thought to protect neural circuits and boost learning and memory, while at the same time increasing when taken in high doses.

In a study published online today in the (PNAS), neuroscientists at USC and the Western University of Health Sciences show that estrogen sometimes acts through another chemical.

Their experiments on mice verified that the hormone stimulates parts of the dedicated to learning and memory.

"We show very clearly that it does activate the same machinery that is activated during learning and memory," said Michel Baudry, professor of neurobiology at the USC College of Letters, Arts and Sciences.

But the researchers also found that estrogen acts through calpain, a protein considered crucial to learning and memory since a seminal paper in 1984 by Baudry and Gary Lynch of the University of California, Irvine on the biochemistry of memory.

Baudry is senior co-author on the PNAS study, which implies that the hormonal description of estrogen needs revisiting.

Estrogen acting through calpain does not work as a slowly diffusing hormone, Baudry said, but as a neurotransmitter with a more powerful and nearly immediate effect on the brain.

He compared estrogen to adrenalin, a substance that acts like a hormone in most of the body but as a neurotransmitter in the brain.

"It's not a hormonal effect. It's a synaptic modulator. It completely changes the way we look at estrogen in the brain," Baudry said.

That change may lead to better drugs against Alzheimer's and other neurodegenerative diseases, according to USC graduate student and lead author Sohila Zadran.

"Estrogen is critically involved in and ," she said, and the PNAS study shows that its effects "critically involve calpain."

In the future, drug developers may choose to target calpain directly, possibly avoiding the risks associated with therapy.

Such a strategy would not have been possible if Baudry's group had not clarified estrogen's mechanism of action.

"If you don't understand the mechanism, it really makes it difficult to go after a problem," Zadran said.

Source: University of Southern California (news : web)

Explore further: Functional brain imaging reliably predicts which vegetative patients have potential to recover consciousness

add to favorites email to friend print save as pdf

Related Stories

Decoy pill saves brain cells

Jan 31, 2007

Tricking a key enzyme can soothe over-excited receptors in the brain, say neuroscientists, calling this a possible strategy against stroke, Alzheimer's and other neurodegenerative diseases.

Improved estrogen reception may sharpen fuzzy memory

Jul 29, 2008

Estrogen treatments may sharpen mental performance in women with certain medical conditions, but University of Florida researchers suggest that recharging a naturally occurring estrogen receptor in the brain may also clear ...

Recommended for you

Advances made in improving error awareness in older people

21 hours ago

(Medical Xpress)—Neuroscientists at Trinity College Dublin have found that people in their 70s are on average less aware of mistakes they make than younger people. The findings may help us develop better methods for helping ...

User comments : 0

More news stories

Low Vitamin D may not be a culprit in menopause symptoms

A new study from the Women's Health Initiative (WHI) shows no significant connection between vitamin D levels and menopause symptoms. The study was published online today in Menopause, the journal of The North American Menopa ...

Patent talk: Google sharpens contact lens vision

(Phys.org) —A report from Patent Bolt brings us one step closer to what Google may have in mind in developing smart contact lenses. According to the discussion Google is interested in the concept of contact ...

Tech giants look to skies to spread Internet

The shortest path to the Internet for some remote corners of the world may be through the skies. That is the message from US tech giants seeking to spread the online gospel to hard-to-reach regions.

Wireless industry makes anti-theft commitment

A trade group for wireless providers said Tuesday that the biggest mobile device manufacturers and carriers will soon put anti-theft tools on the gadgets to try to deter rampant smartphone theft.