CONSERVED AND SEXUALLY DIMORPHIC BEHAVIORAL-RESPONSES TO BIOGENIC-AMINES IN DECAPITATED DROSOPHILA

A preparation of decapitated Drosophila melanogaster has been used for direct application of drugs to the nerve cord. Serotonin, dopamine, a nd octopamine stimulate locomotion and grooming, showing distinguishab le effects that often are potentiated by addition of the vertebrate mo noamine oxidase-inhibitor hydrazaline. Many of the hydrazaline-induced effects are sexually dimorphic, with males showing greater responses than females. Behaviors similar to those induced by dopamine can be in duced by application of the vertebrate dopamine D2-like receptor agoni st quinpirole, whose effects are also sexually dimorphic. In contrast, vertebrate D2-like and D1-like dopamine antagonists result in akinesi c states, and D1-like agonists selectively stimulate grooming. These d ata indicate that Drosophila nerve cord amine receptors are coupled to reflexive behaviors similar to those stimulated by brain dopamine rec eptors in vertebrates.