A species of tropical butterfly with unusually expanded brain structures displays a fascinating mosaic pattern of neural expansion linked to a cognitive innovation.

The study, published in Current Biology, investigates the neural foundations of behavioral innovation in Heliconius butterflies, the only genus known to feed on both nectar and pollen. As part of this behavior, they demonstrate a remarkable ability to learn and remember spatial information about their food sources—skills previously connected to the expansion of a brain structure called the mushroom bodies, responsible for learning and memory.

Highlights

• Heliconiini butterflies have conserved wiring logic in spheroid mushroom body lobes

• Kenyon cell populations expanded to differing degrees in Heliconius butterflies

• Increased numbers of feedback neurons and conservation in dopaminergic neurons

• Mosaic evolution to facilitate cognitive processes associated with pollen feeding