CIRCADIAN CONTROL OF BEHAVIOR
Circadian systems evolved as a mechanism that allows organisms to maintain internal temporal order and anticipate the daily environmental changes caused by the rotation of Earth. Although the biochemical components underlying the molecular oscillations have been well characterized, less is known about the physiological mechanisms that connect clock neuron networks to their output pathways and allow the circadian control of physiology and behavior.
Timing of behavioral outputs is essential for survival, as it determines an animal`s ability to be physiologically ready for resources and potential mates. Many behaviors are under clock control, including sex-specific, reproduction-associated behaviors such as courtship and aggression. Drosophila is a powerful model system in which to study the neuronal basis of sexual dimorphism in timekeeping thanks to its well characterized circadian clock neuron network and highly conserved physiology. Our long term goal is to understand how differences in the underlying architecture of the timekeeping system in the Drosophila brain underlie sex differences in sleep/wake cycles and their robustness in the face of changing environmental conditions.
NEUROBIOLOGY OF AGGRESSION
Aggression is a complex social behavior that likely evolved in the context of competition for resources. Although interactions between genes, environmental signals, and hormones influence the manifestation of aggression, the core circuitry underlying aggressive behavior appears to be hardwired in the nervous system, as animals with no previous social experience can engage in normal agonistic encounters As. for most species, aggression in Drosophila melanogaster is sex-specific, suggesting that it is differentially hardwired in the nervous systems of males and females. The study of innate sexually dimorphic behaviors in genetically tractable organisms offers unique opportunities to understand how the underlying neuronal circuitry is genetically specified.