Differential control of aggression by the midbrain.

Electrical stimulation of the midbrain tegmentum can produce differential modulation of quiet biting attack and affective defense behavior elicited from the hypothalamus of the cat. Stimulation of the lateral half of the tegmentum facilitated quiet biting attack and suppressed affective defense. Conversely, stimulation of the medial tegmentum suppressed quiet biting attack and facilitated affective defense. These results clearly indicate a topographic organization of modulatory sites controlling hypothalamic aggression within the midbrain tegmentum.