Octopamine neuron dependent aggression requires dVGLUT from dual-transmitting neurons

• Published in: PLoS genetics 2020-02, Vol.16 (2), p.e1008609-e1008609
• Main Authors: Sherer, Lewis M, Catudio Garrett, Elizabeth, Morgan, Hannah R, Brewer, Edmond D, Sirrs, Lucy A, Shearin, Harold K, Williams, Jessica L, McCabe, Brian D, Stowers, R Steven, Certel, Sarah J
• Format: Article
• Language: English
• Subjects: Aggression; Amino acids; Animals; Animals, Genetically Modified; Behavior; Behavior, Animal; Biology; Biology and Life Sciences; Brain; Courtship; Displays (Marketing); Dopamine; Drosophila; Drosophila melanogaster - physiology; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Female; Glutamate; Glutamatergic transmission; Glutamic Acid - metabolism; Insects; Localization; Male; Males; Medicine and Health Sciences; Monoamines; Nervous system; Neuromodulation; Neurons; Neurons - metabolism; Neurosciences; Neurotransmission; Neurotransmitters; Octopamine; Octopamine - metabolism; Research and Analysis Methods; Schizophrenia; Sex Factors; Signal Transduction - genetics; Social aspects; Social behavior; Social organization; Social Sciences; Synaptic Transmission - genetics; Synaptic Vesicles - metabolism; Telecommunications equipment; Vesicular Glutamate Transport Proteins - genetics; Vesicular Glutamate Transport Proteins - metabolism; Vesicular Monoamine Transport Proteins - metabolism
• ISSN: 1553-7404; 1553-7390; 1553-7404
• DOI: 10.1371/journal.pgen.1008609

Neuromodulators such as monoamines are often expressed in neurons that also release at least one fast-acting neurotransmitter. The release of a combination of transmitters provides both "classical" and "modulatory" signals that could produce diverse and/or complementary effects in associated circuits. Here, we establish that the majority of Drosophila octopamine (OA) neurons are also glutamatergic and identify the individual contributions of each neurotransmitter on sex-specific behaviors. Males without OA display low levels of aggression and high levels of inter-male courtship. Males deficient for dVGLUT solely in OA-glutamate neurons (OGNs) also exhibit a reduction in aggression, but without a concurrent increase in inter-male courtship. Within OGNs, a portion of VMAT and dVGLUT puncta differ in localization suggesting spatial differences in OA signaling. Our findings establish a previously undetermined role for dVGLUT in OA neurons and suggests that glutamate uncouples aggression from OA-dependent courtship-related behavior. These results indicate that dual neurotransmission can increase the efficacy of individual neurotransmitters while maintaining unique functions within a multi-functional social behavior neuronal network.