In this story from Nature, "Surprise 'mystery' neurons found in male worms" the title gives it away.
The neurons help the worms learn when to prioritize mating over eating, revealing how a seemingly simple brain can be capable of a complex learned behaviour — and one that differs between the sexes.So it looks like there's more work to be done to get a good handle on the worm brain.
Caenorhabditis elegans worms are the model animal of choice for many neuroscientists, because their neural circuits are so simple that they can be mapped in full. They have two sexes: hermaphrodite and male. Hermaphrodites, the best studied, have just 302 neurons, but males have more — the MCMs raise their total to 385 neurons.