The main function of brains is to generate adaptive behavior. Far from being the stereotypical, robot-like insect, the fruit fly Drosophila exhibits astounding flexibility and chooses different courses of actions even under identical external circumstances. Due to the power of genetics, we now are beginning to understand the neuronal mechanisms underlying this behavioral flexibility. Interestingly, the evidence from studies of disparate behaviors converges on common organizational principles common to many if not all behaviors, such as modified sensory processing, involvement of biogenic amines in network remodeling, ongoing activity, and modulation by feedback. Seemingly foreseeing these recent insights, the first research fields in Drosophila behavioral neurogenetics reflected this constant negotiation between internal and external demands on the animal as the common mechanism underlying adaptive behavioral choice in Drosophila.
Do insects, like other animals, expect future events, predict the value of potential actions, and decide between behavioral options without having access to the indicating stimuli? These cognitive capacities are captured by the term intentionality. This chapter addresses the question at two levels, behavior and neural correlates. Behavioral studies are performed with freely flying bees in the natural environment and with harnessed bees in the laboratory by applying the proboscis extension response paradigm. Data are presented and discussed on context-dependent learning, selective attention, rule learning, navigation, communication, and sleep-dependent memory consolidation. Although behavioral analyses document the rich repertoire and the cognitive dimensions of honeybee behavior, intentionality is nearly impossible to prove by behavioral analyses only and neural correlates are essential.