Effects of experimental temporal lobe seizures upon hypothalamically elicited aggressive behavior in the cat

An experiment was performed in order to determine the effects of temporal lobe seizures upon hypothalamically elicited aggressive behavior in the cat. Seizures were induced by electrical stimulation of the pyriform cortex or those subnuclei of the amygdala which had previously been shown to modulate aggressive responses at subseizure current levels. The results clearly indicate that a significant modification of affective defense thresholds following seizures was a direct function of the locus of stimulation. Specifically, seizures generated from the pyriform cortex and medial aspects of the amygdala (sites associated with prior facilitation of affective defense as determined by subseizure electrical stimulation) were followed by a reduction in threshold for this response. In contrast, an elevation in affective defense thresholds occurred when seizures were generated from the central or lateral nuclei of the amygdala (sites associated with prior suppression of affective defense as determined by subseizure electrical stimulation). The primary pathway utilized in the facilitation of affective defense appears to involve the stria terminalis, its bed nucleus, and the anterior medial hypothalamus. Preliminary data suggest that seizures generated from the pyriform cortex or amygdala can also modify quiet biting attack behavior, but in a manner opposite to that demonstrated for affective defense.