VMHvl-Projecting  <i>Vglut1</i>+Neurons in the Posterior Amygdala Gate Territorial Aggression

Abstract

Despite being innate, display of aggression is influenced by cortical activities. Here, using Vglut1 as a marker for inputs from cortical structures, we identified a small population of excitatory neurons located in the posterior amygdala (PA) that projects to the ventrolateral division of ventromedial nucleus of the hypothalamus (VMHvl), a region that critically regulate territorial aggression. Indeed, activities of PA Vglut1+ (PA Vglut1 ) neurons, as analyzed by post-hoc c-Fos expression, unequivocally differentiate trials in which attacks occur or not during resident-intruder assays. More importantly, chemogenetic activation of VMHvl-projecting PA Vglut1 neurons robustly promotes aggression while inhibition of these neurons reduces attacks. Finally, connectivity map places VMHvl-projecting PA Vglut1 neurons at the interface between emotion reactivity and aggression as they receive broad inputs from limbic structures and project collaterally to VMHvl and other targets. Taken together, these results point to VMHvl-projecting PA Vglut1 neurons as a potential site for cortical gating of territorial aggression.