GILLETTE, Rhanor*; YAFREMAVA, Liudmila; University of Illinois at Urbana-Champaign; University of Illinois at Urbana-Champaign: Evolution and Function in Serotonergic Systems

Serotonin was first identified as a neurotransmitter in clams, and then mammalian brain. The history of its evolution as an intercellular messenger and CNS neurotransmitter is only recently begun to be appreciated through comparative studies of vertebrates and invertebrates. Lophotrochozoans (snails and leeches), insects and decapod crustaceans have been intensively studied for the past five decades as accessible model systems for studying neural bases of behavior. A natural fallout has been the accumulation of a broad base of knowledge of the chemistry and functions of serotonin in neural networks. Parallels and contrasts can be drawn for the anatomy and neuropharmacology of serotonin in the protostome invertebrates and mammals that suggest considerable serotonergic function has been conserved, despite marked divergence in anatomy and behavior. Integrative, comparative studies of the neurotransmitter can yield insight for how its contemporary roles in behavior and development arose.