IT’S true - sex does change things, including the structure of rats’ brains. And another thing - it really is different for males and females. There are several brain regions linked to sexual behaviour that differ in size between the sexes in humans and other mammals. To find out whether a region known to be bigger in males was altered by sex, Shinji Tsukahara and his colleagues at Saitama University near Tokyo, Japan, compared the brains of male rats who had never had sex before with their more experienced counterparts. They found that the number of spiny structures located at the neuronal synapses was significantly lower in rats that had copulated.
