Collaborative Research: Brain Plasticity and Division of Labor- From Simple to Complex Societies

University Of Washington, Seattle WA

Investigators

Abstract

Social insects are among the most ecologically dominant terrestrial animals. Their success is largely attributed to division of labor among the workers that make up their colonies. Individual differences in worker behavior are governed by physiological and anatomical changes in the nervous system, particularly in the brain. However, the dynamic properties of brain neurons that influence worker behavior are poorly understood. The goal of this project is to study how changes in brain neurons are associated with division of labor among social insect workers, focusing on neural plasticity in the mushroom bodies (MB). MB are structures in insect forebrains that are involved in learning and sensory integration, and the MB may play an important role in regulating division of labor. As a first step toward understanding the evolution of MB effects on behavior, the relationships of MB neuroanatomy and worker behavior will be compared between a wasp species with small, simple societies (Mischocyttarus mastigophorus) and a species with larger, more complex colonies (Polybia aequatorialis). Three main approaches will be used. In the first study, MB neurons that are associated with individual differences in task performance will be identified. In the second study the effects of age on MB neuron plasticity and worker behavior will be measured. In the third study, colonies will be manipulated to induce changes in worker behavior, and associated neural changes will be measured. The proposed projects include graduate and undergraduate training opportunities, and will provide inter-institutional training experiences. They will also promote education for Americans and local residents in Costa Rica, including biology guides (Monteverde Cloud Forest Reserve), and students on graduate and undergraduate field courses. Ongoing investigations in Monteverde will enhance the visibility of basic investigation at this important tropical research and conservation site. The research findings may also have relevance to the control/management of social insect pests and beneficial insects.