Researchers have found a pair of neurons that help to remember and seek sex even at the expense of food in male worms. These male-specific neurons are required for sex-based differences in learning, thus suggesting that sex differences in cognitive abilities can be genetically hardwired. These findings could have important therapeutic implications in the future.
Senior author Dr. Arantza Barrios from University College London said, "Areas of the brain involved in learning display sex differences in many animals, including humans, but how these differences directly affect behavior is not clear."
The research team has shown how genetic and developmental differences between the two sexes lead to structural changes in the brain of male worms during sexual maturation. Dr. barrios said, "These changes make male brains work differently, allowing males to remember previous sexual encounters and prioritize sex in future situations."
The researchers were surprised to find previously unidentified cells that are responsible for the behavioral change as worms are an extremely well studied model organism. The investigators 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 called as 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. The 'MCM' neurons are only made from glial cells that have male chromosomes.
Co-author professor Scott Emmons from Albert Einstein College of Medicine said, "Though the work is carried out in a small worm, it nevertheless gives us a perspective that helps us understand the variety of human sexuality, sexual orientation and gender identification. The scientists can now exploit this system to understand how fully differentiated glia can re-enter the cell cycle and generate neurons."
The study was published in Nature.