Extra brain cells make males remember sex

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. This is important as very little is known about how brains vary to give the two sexes different preferences, aptitudes and judgments. Harold & Leila Y. Mathers Charitable Foundation, shows a direct link between contrasting behaviour of male and female worms and differences in brain development and structure in areas involved in higher order processing. Senior author Dr Arantza Barrios, UCL Cell & Developmental Biology, said: "Areas of the brain involved in learning display sex differences in many animals, including humans, but how these differences directly affect behaviour is not clear. "We've shown how genetic and developmental differences between the two sexes lead to structural changes in the brain of male worms during sexual maturation. These changes make male brains work differently, allowing males to remember previous sexual encounters and prioritise sex in future situations." The team were surprised to find previously unidentified cells are responsible for the behavioural change, as worms are an extremely well studied model organism.