By Jim Barlow Can honey bees help scientists understand how adult humans learn? Researchers at the UI are convinced they can. In the July 15 issue of the journal Nature, they describe structural changes that occur in the brains of bees when the insects leave their domestic chores to tackle their most challenging and complex task - foraging for pollen and nectar. As part of a doctoral thesis, neuroscience graduate student Ginger S. Withers focused on the "mushroom bodies," a region of the insect brain so named because it appears mushroom-shaped when viewed in cross-section. The region is closely associated with learning and memory. Withers used quantitative neuroanatomical methods to study sections of bee brains to show that the mushroom bodies are reorganized when a bee becomes a forager. Although a honey bee typically switches from hive-keeping tasks, such as rearing younger sisters and caring for the queen, to foraging at about three weeks of age, the brain changes are not simply due to aging. In a key experiment, young honey bees were forced to become foragers by removing older bees from the colony. The mushroom bodies of the precocious foragers, who were only about 1 week old, mirrored those of normal-aged foragers. The findings suggest that nerve cells in the mushroom bodies receive more informational inputs per cell as the bee learns to forage. In order to be a successful forager, a bee must learn how to navigate to and from its hive and how to collect food efficiently from many different types of flowers. The implications for neuroscience go far beyond the beehive, said the article's co-authors, UI insect biologists Susan E. Fahrbach and Gene E. Robinson. There could be application to human studies, they said, because the structure of bee brains is similar to - but much simpler than - human brains. Fahrbach, whose research has focused on the impact of hormones on the nervous system, was drawn to the honey bee by its sophisticated behavior, small brain and power of concentration. "Honey bees offer an exceptionally powerful model for the study of changes in the brain related to naturally occurring changes in behavior, because, once a bee becomes a forager, it does nothing else," she said. "Because the behavioral shifts are so complete, the changes in brain structure that accompany the behavioral transitions must be related to the performance of the new observed behavior." Robinson, who is director of the UI's Bee Research Facility and who has previously studied other physiological and genetic aspects of bee behavior, agrees: "This discovery opens a new area of research on the relationship between brain and behavioral plasticity. One fundamental question this research raises is 'which comes first?' Do changes in behavior lead to changes in brain structure? Or do the changes in brain structure occur first, in preparation for the changes in behavior?" As researchers pursue the changes in brain cells that form the underpinnings of learning, the UI scientists say the combination of neuroscience and entomology may yield sweet rewards.