Men and women can seem like they’re from different planets sometimes. Hormones help drive those differences. A new study shows how genes pass on the message. Hormones are the body's signaling molecules. They affect many aspects of development and biology. Researchers have long known that the sex hormones, such as estrogen and testosterone, drive certain differences in behavior between men and women. How these hormones exert their effects on a molecular level, however, isn't well understood. A team of scientists used DNA microarrays to analyze gene expression across the mouse brain. They particularly focused on the hypothalamus, a region known to be involved with hormone sensing. The team reported finding 16 genes that were expressed differently between the brains of male and female mice. A closer look revealed that these sex differences in gene expression weren’t limited to the hypothalamus. They were also found in the amygdala, a region implicated in processing emotions. These results also suggest that other complex behaviors might be similarly constructed by gene networks. Of course, genes aren't the only things that drive how people behave. But this research shows that genes may play an important role in complex human behavior.
