Estrogen Influences the Brain's Sound Processor

Thus far, the estrogen hormone, of which women have more, has been known only for its effects on determining the female traits and for its role on the reproductive system. But a brand new study conducted by researchers at the University of Rochester comes to show that the stuff also plays a pivotal part in the way the brain processes sounds and also in the way it deals with memories. After proving that estrogen can directly influence the auditory function, the UR experts have also hypothesized that it can affect other sensory processes as well.

“We've discovered estrogen doing something totally unexpected. 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,” UR Assistant Professor of Brain and Cognitive Sciences Raphael Pinaud explains. He is also the lead author of a new scientific paper detailing the finds, which appears in the May 5th issue of The Journal of Neuroscience.

“It turns out that estrogen plays a dual role. It modulates the gain of auditory neurons instantaneously, and it initiates cellular processes that activate genes that are involved in learning and memory formation. Based on our findings we must now see estrogen as a central regulator of hearing. 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,” the expert adds.

The way the researchers have demonstrated the effects of estrogen has been a very direct one. They simply subjected the parts of the brain known to deal with processing the auditory sensation to increased dosages of the hormone. The team, made up of Pinaud, research Assistant Professor of Brain and Cognitive Sciences Liisa Tremere, and postdoctoral fellow Jin Jeong, immediately noticed a heightened sense of auditory perception in study participants. The way this happened was through the fact that increased amounts of estrogen in neurons in those areas caused the brain cells to identify more subtle sound components.

The research group also managed to shed some light on the mystery of why women who reached menopause – when hormone levels become imbalanced, and eventually drop – experienced a significant decline in their sound-processing abilities. “While we are currently conducting further experiments to confirm it, we believe that our findings extrapolate to other sensory systems and vertebrate species. If this is the case, we are on the way to showing that estrogen is a key molecule for processing information from all the senses,” Pinaud concludes.