Neurocircuitry of aggression and aggression seeking behavior: nose poking into brain circuitry controlling aggression

Abstract

Aggression is an innate behavior that helps individuals succeed in environments with limited resources. Over the past few decades, neurobiologists have identified neural circuits that promote and modulate aggression; however, far less is known regarding the motivational processes that drive aggression. Recent research suggests that aggression can activate reward centers in the brain to promote positive valence. Here, we review major recent findings regarding neural circuits that regulate aggression, with an emphasis on those regions involved in the rewarding or reinforcing properties of aggressive behavior.

Figure 1. Neural Circuitry of Aggression

Schematic map of the brain areas and their neuronal connection that are involved in aggressive behavior in mice reviewed in this paper. Areas that stimulate aggression are shaded in “pink” and areas that suppress aggression are shaded in “blue”. Medial amygdala (MeA) is shaded in “violet” and since it can both stimulate and suppress aggression depending on neuronal output that is optogenetically stimulated. AVPV: anteroventral periventricular nucleus of hypothalamus. DRN: dorsal raphe nucleus. LHb: lateral habenula. MeA: Medial amygdala. MPOA: medial preoptic area. NAc: nucleus accumbens. VMHvl: ventrolateral area of ventromedial hypothalamus. VTA: ventral tegmental area. (Dashed line denotes neuronal pathways that have been identified but not studied in the context of aggression or aggression-seeking behavior. The question mark [?] reflects the fact that although highly possible, dopaminergic nature of these neurons yet to be proven).

Figure 2

Behavioral tests to evaluate aggression-seeking behavior: A: Aggression conditioned place preference apparatus. B: Operant aggression-seeking box (Courtesy of Dr Sam Golden and Dr. Yavin Shaham, NIH).