Hippocampal EEG Correlates of Intraspecies Aggressive Behavior in the Rat

Abstract

EEG was recorded from the dorsal hippocampus of adult albino rats during aggressive interactions with experienced dominant conspecifics. During the encounters, immobility of the recorded animal in all postures of defense or submission was accompanied by hippocampal large irregular activity (LIA) even when the dominant opponent was threatening or attacking, and, in a few instances, actually biting the animal. LIA was also recorded during the movements of autogrooming, allogrooming and ''waxy'' postural shifts, whereas RSA (rhythmical slow activity) accompanied all other recorded movements including ''boxing'' with forepaws, evasive movements, postural shifts, and walking. The results suggest that during aggressive encounters the pattern of hippocampal EEG activity depends closely upon the topography of ongoing motor behavior.