From the WUSTL Newsroom…
Few things are as interesting to a male mouse as the scent of a female. Pheromones released by females draw the attention of male mice and trigger courtship and mating behavior.
Now, researchers at Washington University School of Medicine in St. Louis have found a specific kind of neuron only in male mice that detects a pheromone in female urine. But the sex difference is not hard-wired. By manipulating the mice’s living conditions and exposing male mice to female scents for long periods of time, the scientists showed that males lost these neurons and their interest in courting females.
The study, published Aug. 17 in Neuron, describes how neurons in the nose adapt to experience, and helps explain differences among individuals and between the sexes.
“Obviously people have different brains. We think differently, we act differently,” said Timothy E. Holy, PhD, an associate professor of neuroscience and the study’s senior author. “There’s been a lot of interest over the years in trying to understand what it is that makes one brain different than another brain. In this case, the differences between males and females was due not to innate factors – as you might expect for a pheromone-sensing system – but instead to different sensory experiences.”
Holy and former graduate student Pei Sabrina Xu, PhD, screened hundreds of thousands of neurons in mice’s vomeronasal organs, a structure in the nose that detects pheromones as well as other chemical signals. The vast majority of the neurons were the same between the sexes, but one subset was present in the males but absent from the females. That subset specifically detects epitestosterone sulfate, a possible byproduct of sex hormones.
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