Estrogen controls how the brain processes sound

May 05, 2009
Estrogen controls how the brain processes sound
This is Liisa Tremere, Jin Jeong, and Raphael Pinaud. Credit: University of Rochester

Scientists at the University of Rochester have discovered that the hormone estrogen plays a pivotal role in how the brain processes sounds.

The findings, published in today's issue of The Journal of Neuroscience, show for the first time that a sex hormone can directly affect auditory function, and point toward the possibility that estrogen controls other types of sensory processing as well. Understanding how estrogen changes the brain's response to sound, say the authors, might open the door to new ways of treating hearing deficiencies.

"We've discovered estrogen doing something totally unexpected," says Raphael Pinaud, assistant professor of brain and cognitive sciences at the University of Rochester and lead author of the study. "We show that estrogen plays a central role in how the brain extracts and interprets auditory information. It does this on a scale of milliseconds in neurons, as opposed to days, months or even years in which estrogen is more commonly known to affect an organism."

Previous studies have hinted at a connection between estrogen and hearing in women who have low estrogen, such as often occurs after menopause, says Pinaud. No one understood, however, that estrogen was playing such a direct role in determining auditory functions in the brain, he says. "Now it is clear that estrogen is a key molecule carrying brain signals, and that the right balance of hormone levels in men and women is important for reasons beyond its role as a sex hormone," says Pinaud.

Pinaud, along with Liisa Tremere, a research assistant professor of brain and cognitive sciences, and Jin Jeong, a postdoctoral fellow in Pinaud's laboratory, demonstrated that increasing estrogen levels in that process auditory information caused heightened sensitivity of sound-processing neurons, which encoded more complex and subtle features of the sound stimulus. Perhaps more surprising, says Pinaud, is that by blocking either the actions of estrogen directly, or preventing brain cells from producing estrogen within auditory centers, the signaling that is necessary for the brain to process sounds essentially shuts down. Pinaud's team also shows that estrogen is required to activate genes that instruct the to lay down memories of those sounds.

"It turns out that estrogen plays a dual role," says Pinaud. "It modulates the gain of auditory neurons instantaneously, and it initiates cellular processes that activate genes that are involved in learning and memory formation."

Pinaud and his group stumbled upon these findings while investigating how estrogen may help change neuronal circuits to form memories of familiar songs in a type of bird typically used to understand the biology of vocal communication. "Based on our findings we must now see estrogen as a central regulator of hearing," he says. "It both determines how carefully a sound must be processed, and activates intracellular processes that occur deep within the cell to form memories of sound experiences."

Pinaud and his team will continue their work investigating how neurons adapt their functionality when encountering new sensory information and how these changes may ultimately enable the formation of memories. They also will continue exploring the specific mechanisms by which estrogen might impact these processes.

"While we are currently conducting further experiments to confirm it, we believe that our findings extrapolate to other sensory systems and vertebrate species," says Pinaud. "If this is the case, we are on the way to showing that is a key molecule for processing information from all the senses."

Source: University of Rochester (news : web)

Explore further: Neurobiology online course to attempt world's largest memory experiment

add to favorites email to friend print save as pdf

Related Stories

Sex hormone signaling helps burn calories

Feb 26, 2007

Any dieter can tell you: Body weight is a function of how much food you eat and how much energy you use. The trick to maintaining a healthy weight lies in regulating the balance. Now new research from Rockefeller ...

Fertile? Not Without the Brain

Oct 20, 2006

There are many causes of infertility. The fact that nerve cells can also play a role is little known. The hormone estrogen regulates the activity of neurons that give the starting signal for ovulation. Collaborating with ...

Hormones may affect how brain listens

May 03, 2006

From zebra fish to humans, reproductive hormones govern behavioral responses to courtship signals. A new Emory University study conducted in songbirds suggests that hormones may also modulate the way the auditory system processes ...

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 ...

Is that song sexy or just so-so?

Sep 22, 2008

Why is your mate's rendition of Marvin Gaye's "Let's Get it On" cute and sexy sometimes and so annoying at other times? A songbird study conducted by Emory University sheds new light on this question, showing that a change ...

Recommended for you

User comments : 0

More news stories

FDA proposes first regulations for e-cigarettes

The federal government wants to prohibit sales of electronic cigarettes to minors and require approval for new products and health warning labels under regulations being proposed by the Food and Drug Administration.

When things get glassy, molecules go fractal

Colorful church windows, beads on a necklace and many of our favorite plastics share something in common—they all belong to a state of matter known as glasses. School children learn the difference between ...

FCC to propose pay-for-priority Internet standards

The Federal Communications Commission is set to propose new open Internet rules that would allow content companies to pay for faster delivery over the so-called "last mile" connection to people's homes.

SK Hynix posts Q1 surge in net profit

South Korea's SK Hynix Inc said Thursday its first-quarter net profit surged nearly 350 percent from the previous year on a spike in sales of PC memory chips.

Brazil enacts Internet 'Bill of Rights'

Brazil's president signed into law on Wednesday a "Bill of Rights" for the digital age that aims to protect online privacy and promote the Internet as a public utility by barring telecommunications companies ...