Hypothalamic attack area-mediated activation of the forebrain in aggression.

It is believed that aggressive attacks are activated by a downward stimulatory stream that includes the medial amygdala, hypothalamic attack area, and periaqueductal grey. However, the hypothalamic attack area (from which attacks can be induced by electrical stimulation) sends projections to the forebrain, the significance of which is unknown. Here we report that the unilateral stimulation of the hypothalamic attack area per se induced an unilateral c-Fos activation of most brain nuclei involved in attack, and that attacks occurred only when cortical regions were also activated, and the activation of the medial amygdala and hypothalamic attack area were bilateral. This suggests that the hypothalamic attack area not only transmits information to lower brain structures but also activates forebrain structures involved in attack.