A pair of neurons have been found in the brain of male nematode worms that allow them to remember and seek sex even at the expense of food.
These neurons, which are male-specific, are required for sex-based differences in learning, suggesting that sex differences in cognitive abilities can be genetically hardwired.
Scientists were able to show that the cells from which these male brain neurons are born share common characteristics to the cells that give rise to human brain neurons. They are glial cells – companion and support cells of neurons.
The newly identified pair of neurons – called ‘mystery cells of the male’ or ‘MCMs’ – create behavioral differences between the sexes by changing a brain circuit common to both. Whether the neurons are born or not depends on the genetic sex of the glial cells from which they arise and not on the sex of the animal or on hormones. The MCM neurons are only made from glial cells that have male chromosomes.
They found that the MCMs connected with neurons that are present in both sexes and that the presence of MCMs only in males remodeled these circuits to change the way information is processed.