According to a new study led by Stanford University and published in the journal Cell, male and female mouse brains differ significantly.
By probing four tiny structures within mouse brains that are known to be responsible for the so-called “rating, dating, mating, and hating” behaviors, the scientists found over 1,000 genes with different activity levels in the brains of one sex versus the other. Although this study focused on mice, the sex differences are likely to occur in the brains of humans too.
Male mice, for example, are able to quickly determine the sex of strangers intruding on their territory. The mice attack the strangers if they are male, or start courting them if they are female.
By contrast, female mice exhibit maternal rather than territorial aggression, and are much more genetically inclined to protect their pups than males. Moreover, their willingness to mate is strongly related to the stage of their estrous cycle.
“These primal behaviors are essential to survival and reproduction, and they’re largely instinctive,” and determined by the differential activation of various genes, explained study senior author Nirao Shah… “Using these genes as entry points, we’ve identified specific groups of brain cells that orchestrate specific sex-typical behaviors.”