Reorganization of the Central Nervous Systems in Response to Changes in Social Environment Among Insects

Caste is a polyphenism for efficiently accomplishing various tasks in a group for social insects, and morphological differentiation is based on nutritional conditions in larval development. Adult worker insects can plastically convert part of their internal organs and behaviors to those of a queen while maintaining external morphology as is. Behavioral change together with caste transition is caused by physiological change in the brain, and behavioral change affects even the brain morphologically, eventually creating an “adaptive” brain specialized in caste. This phenomenon, a typical example of “mobiligence,” is a model case in which physiological and morphological transitions in the brain are detected.