Octopamine neuromodulation regulates Gr32a-linked aggression and courtship pathways in Drosophila males.
Chemosensory pheromonal information regulates aggression and reproduction in many species, but how pheromonal signals are transduced to reliably produce behavior is not well understood. Here we demonstrate that the pheromonal signals detected by Gr32a-expressing chemosensory neurons to enhance male aggression are filtered through octopamine (OA, invertebrate equivalent of norepinephrine) neurons. Using behavioral assays, we find males lacking both octopamine and Gr32a gustatory receptors exhibit parallel delays in the onset of aggression and reductions in aggression. Physiological and anatomical experiments identify Gr32a to octopamine neuron synaptic and functional connections in the suboesophageal ganglion. Refining the Gr32a-expressing population indicates that mouth Gr32a neurons promote male aggression and form synaptic contacts with OA neurons. By restricting the monoamine neuron target population, we show that three previously identified OA-Fru(M) neurons involved in behavioral choice are among the Gr32a-OA connections. Our findings demonstrate that octopaminergic neuromodulatory neurons function as early as a second-order step in this chemosensory-driven male social behavior pathway.
Center for Structural and Functional Neuroscience, University of Montana, Missoula, Montana, United States of America.
Jonathan C
JC
Andrews
Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, United States of America.
María Paz
MP
Fernández
Center for Structural and Functional Neuroscience, University of Montana, Missoula, Montana, United States of America.
Qin
Q
Yu
Center for Structural and Functional Neuroscience, University of Montana, Missoula, Montana, United States of America.
Greg P
GP
Leary
Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, United States of America.
Adelaine K W
AK
Leung
Center for Structural and Functional Neuroscience, University of Montana, Missoula, Montana, United States of America.
Michael P
MP
Kavanaugh
Department of Neurobiology, Harvard Medical School, Boston, Massachusetts, United States of America.
Edward A
EA
Kravitz
Center for Structural and Functional Neuroscience, University of Montana, Missoula, Montana, United States of America; Division of Biological Sciences, University of Montana, Missoula, Montana, United States of America.
Sarah J
SJ
Certel
D000374:Aggression; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D001522:Behavior, Animal / Q000502:physiology*; D017931:DNA Primers; D004330:Drosophila / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology*; D009655:Octopamine / Q000502:physiology*; D016133:Polymerase Chain Reaction; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology*; D012726:Sexual Behavior, Animal; D015398:Signal Transduction
D017931:DNA Primers; D029721:Drosophila Proteins; C531466:Gr32a protein, Drosophila; D011956:Receptors, Cell Surface; D009655:Octopamine