Sex hormone also decides how well we hear

Oestrogen, a sex hormone, also has a vital bearing on how our brain processes sounds, according to a new discovery.

The findings show for the first time that a sex hormone can directly affect auditory function, and seemingly control other types of sensory processing as well.

Understanding this process, the authors said, might open the door to new ways of treating hearing deficiencies.

"We've discovered oestrogen doing something totally unexpected," said Raphael Pinaud, assistant professor of brain and cognitive sciences at the University of Rochester, who led the study.

"We show that oestrogen 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 oestrogen is more commonly known to affect an organism."

Previous studies have hinted at a connection between oestrogen and hearing in women who have low oestrogen levels, often after menopause, said Pinaud.

No one understood, however, that oestrogen was playing such a direct role in determining auditory functions in the brain, he said, according to a Rochester release.

"Now it is clear that oestrogen 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," said Pinaud.

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

These findings were published in the current issue of The Journal of Neuroscience.