Octopamine neuron dependent aggression requires dVGLUT from dual-transmitting neurons

• DOI: 10.1371/journal.pgen.1008609
• Publication Date: 2020-02-25T18:53:11Z
• Authors: Lewis M. Sherer; Elizabeth Catudio...; Hannah R. Morgan; Edmond D. Brewer; Lucy A. Sirrs; Harold K. Shearin; Jessica L. Williams; Brian D. McCabe; R. Steven Stowers; Sarah J. Certel
• Keywords: Male; Glutamic Acid; vesicular glutamate transporter; QH426-470; Synaptic Transmission; Animals, Genetically Modified; 03 medical and health sciences; Sex Factors; synaptic vesicles; expression; Vesicular Glutamate Transport Proteins; Genetics; Animals; Drosophila Proteins; Octopamine; Neurons; drosophila-melanogaster; 0303 health sciences; Behavior, Animal; amino-acid transporters; Courtship; dopamine neurons; 3. Good health; Aggression; Drosophila melanogaster; cerebral-cortex; temporal-lobe; Vesicular Monoamine Transport Proteins; Female; Synaptic Vesicles; corelease; model system; Research Article; Signal Transduction

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.