The study published in Current Biology explores the neural foundations of behavioural innovation in Heliconius butterflies, focusing on the expansion of brain structures associated with cognitive abilities such as learning and memory. The researchers found that certain groups of cells within the butterfly brain, known as Kenyon cells, expanded at different rates, leading to a mosaic pattern of neural expansion. This mosaic brain evolution is believed to be linked to specific shifts in behavioural performance, such as the butterflies’ ability to learn and remember spatial information about their food sources.
Heliconius butterflies, the only genus known to feed on both nectar and pollen, demonstrate a remarkable ability to learn and remember spatial information about their food sources, requiring efficient routes of feeding as pollen plants are rare. The butterflies exhibit fixed routes between floral resources, similar to a bus route, indicating a level of planning and memory processes fulfilled by the neural circuits within their brains, particularly the mushroom bodies responsible for learning and memory. The study suggests that specific aspects of these circuits have been modified to enhance the cognitive capacities of Heliconius butterflies.
The researchers aim to further explore how neural circuits change to reflect cognitive innovation and change, using insects as tractable model systems to reveal genetic and cellular mechanisms common to all neural circuits. By studying the neural circuits in Heliconius butterflies, the team hopes to bridge the gap to other organisms, potentially shedding light on the mechanisms underlying cognitive abilities in humans. Future research will focus on expanding brain mapping to visualize how individual neurons connect at a more granular level, beyond the learning and memory centers of the butterfly brain.
The study findings provide insight into the diversity of brain anatomy and evolution, highlighting prominent but distinct changes in neural circuits within Heliconius butterflies. This research offers a unique perspective on the ways in which animals process and use information from their environment, showcasing the intricate interplay between brain structure and cognitive abilities in tropical butterflies. By uncovering the mechanisms underlying cognitive innovation in these butterflies, the study contributes to a deeper understanding of how neural circuits can adapt and evolve to support enhanced behavioural performance.
