Brain metabolism

Zach Coto

What drives the evolution of brain size and brain energy demands? Traditionally, this has been explained by selection for increased cognitive abilities for individual problem solving. Cognition has been thought to be limited by individual brain size and brains are hypothesized to be energetically expensive due to high energetic requirements. However, many insects have microbrains, but perform sophisticated, adaptive behaviors, suggesting that brains can be miniaturized without compromise.

The energy demands of miniaturized brains is unclear. Ants live in societies that use collective behaviors to solve problems intractable for individuals, and the effects of sociality on individual cognition may influence brain energy demands. Therefore, miniaturization and sociality together complicate theories of how brain size and energy demands evolve beyond the simplistic idea that selection for increased individual cognition implies the evolution of larger, costlier brains.

I study the relationship of social complexity and brain size, structure, and metabolism in the ant genus Dolichoderus, which contains species with similar ecology and worker body size, but striking differences in colony size, providing a natural model system to test hypotheses of how variation in sociality relates to variation in brain size, structure and metabolism. I record real-time metabolism from intact living brains. I am also interested in age- and subcaste-related changes in brain metabolic costs.