Neuropharmacology of brain-stimulation-evoked aggression

Evidence is reviewed concerning the brain areas and neurotransmitters invol ved in aggressive behavior in the cat and rodent. In the cat, two distinct neural circuits involving the hypothalamus and FAG subserve two different k inds of aggression: defensive rage and predatory (quiet-biting) attack. The roles played by the neurotransmitters serotonin, GABA, glutamate, opioids, cholecystokinin, substance P, norepinephrine, dopamine, and acetylcholine in the modulation and expression of aggression are discussed. For the rat, a single area, largely coincident with the intermediate hypothalamic area, is crucial for the expression of attack; variations in the rat attack respo nse in natural settings are due largely to environmental variables. Experim ental evidence emphasizing the roles of serotonin and GABA in modulating hy pothalamically evoked attack in the rat is discussed. It is concluded that significant progress has been made concerning our knowledge of the circuitr y underlying the neural basis of aggression. Although new and important ins ights have been made concerning neurotransmitter regulation of aggressive b ehavior, wide gaps in our knowledge remain. (C) 1999 Elsevier Science Ltd. All rights reserved.