Cortical and Limbic Neural Circuits Mediating Aggressive Behavior

Abstract

When a cat is cornered by an attacker, and escape is impossible, the cat displays an unambiguous set of behaviors: the fur stands on end, the pupils dilate, the back arches, the claws are unsheathed, the ears are laid back, the heart rate increases, and the cat may yowl, growl, or bare its teeth and hiss. Finally, if the aggressor persists in spite of these warning signs, the cat will strike to defend itself and fight furiously. This intense defensive-aggression response has been called “affective defense,” “defensive rage behavior,” or simply “rage,” and a similar response occurs in other species. Many brain areas can influence defensive rage (Goddard, 1964; Kaada, 1967; Clemente and Chase, 1973; Ursin, 1981; Albert et al., 1984, 1993; Siegel and Brutus, 1990; Gregg and Siegel, 2001). The available evidence suggests that in humans and animals, similar brain areas are involved (reviewed in Perachio and Alexander, 1975; Lipp and Hunsperger, 1978; Trieman, 1991; Albert et al., 1993; Gregg and Siegel, 2001). This chapter will focus on seven of these areas: the periaqueductal gray of the midbrain (PAG), hypothalamus, septal nuclei, amygdala, prefrontal cortex, bed nucleus of the stria terminalis (BNST), and nucleus accumbens (Fig. 1).