Agonistic behavior in groups of limbic epileptic male rats: pattern of brain damage and moderating effects from normal rats

Different ratios of normal male rats and male rats in which limbic seizures had been induced by a single systemic injection of lithium and pilocarpine were housed in groups of six. The group ratios ranged along the continuum from all normal rats to all experimental rats. The average numbers of episo des of boxing, biting and mounting-thrusting per rat per hour per group wer e recorded by direct observation (red light) for 1 h during the midscotopha se. Groups that contained less than two normal rats exhibited significantly elevated amounts of agonistic (boxing, biting) behavior but not mounting b ehavior. Multiple regression analyses showed that combinations of neuronal loss within only two to three areas accommodated at least 50% of the varian ce in the numbers of these behaviors. (C) 2001 Elsevier Science B.V. All ri ghts reserved.