Neural Mechanisms of Dominance Behavior

Georgia State University Research Foundation, Inc., Atlanta GA

Investigators

Abstract

Lay Abstract: D.H. Edwards (PI), "Neural mechanisms of dominance behavior" The neural bases of dominance hierarchy formation are not well understood. In crayfish and lobster, formation of a dominance hierarchy begins with fighting between pairs of animals in which both animals perform similar behavior patterns: approaches, attacks, and offensive tailflips. At some point, one animal becomes subordinate by switching to defensive behavior and retreating or performing any of three types of escape tailflips. The changes in behavior result from changes in the excitabilities of the neural circuits that mediate the behavior patterns. Changes in circuit excitability may result from changes in neuromodulation of the circuit. Serotonin is one neuromodulator that has been shown to affect escape behavior in a manner that depends on the animal's social status. The present research will determine whether serotonin modulates neural circuits for other behaviors that are important for dominance decisions, including another form of tailflip, backward walking (i.e., retreat), and body posture. The research will also determine whether the serotonergic neurons that normally modulate these circuits are themselves affected by changes in social status. The project will help provide a comprehensive view of the role of serotonergic neuromodulation in the formation of dominance hierarchies by crayfish.