A molecularly distinct cell type in the midbrain regulates intermale aggression behaviors in mice

BackgroundThe periaqueductal gray (PAG) is a central hub for regulation of aggression, while little is known on the circuitry and molecular mechanisms that govern this regulation. We investigate the role of a distinct cell type, Tachykinin 2-expressing (Tac2+) neurons, located in the dorsomedial PAG (dmPAG), in modulating aggression in mice. MethodsWe combined activity mapping, in vivo Ca2+ recording, chemogenetic and pharmacological manipulation, and a viral-based translating ribosome affinity purification (TRAP) profiling using a mouse resident-intruder model. ResultsWe reveal that the dmPAGTac2 neurons were selectively activated during fighting behaviors. Activation of the dmPAGTac2 neurons evoked, while inhibition or genetic ablation of the dmPAGTac2 neurons suppressed fighting behaviors. TRAP profiling of dmPAGTac2 neurons revealed that fighting behaviors specifically induced enrichment of serotonin-associated transcripts to the dmPAGTac2 neurons. Last, we validated these findings by selectively delivering pharmacological agent into the dmPAG and reversed the behavioral outcomes induced by chemogenetic manipulation. ConclusionsWe identify that the dmPAGTac2 neuron can regulate mouse aggressive behavior and thus suggest a distinct molecular target for the treatment of exacerbated aggressive behaviors in populations that exhibit high-level of violence. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/562724v3_ufig1.gif" ALT="Figure 1"> View larger version (75K): org.highwire.dtl.DTLVardef@afc876org.highwire.dtl.DTLVardef@91e355org.highwire.dtl.DTLVardef@1e41e43org.highwire.dtl.DTLVardef@17ef3f1_HPS_FORMAT_FIGEXP M_FIG C_FIG