Is there a relationship between rat latent aggressiveness and susceptibility to convulsive crises?

Experiments were aimed at assessing a possible different sensitiveness to seizures in aggressive vs. nonaggressive rates. Thirty-nine muricidal rats were selected by using a sedated mouse. Six of these killer rats (K) showed electroencephalographic (EEG) spontaneous syncronous wave-and-spike discharges, 6-11 c/s. None of nonkiller animals (NK) showed a similar pattern. These 6 K were not used for the subsequent experiments. Intraperitoneal pentylentetrazole (PTZ; 10, 20, and 40 mg/kg) or bicuculline (BIC; 2 and 4 mg/kg) was given to both NK and K. K were more sensitive than NK to the epileptogenic effects of 20 mg/kg PTZ and 2 mg/kg BIC, as revealed by the significant increased number of convulsive rats and longer duration of EEG seizures. No difference in EEG or convulsant behavior was observed between K and NK after the administration of the lower dose of PTZ and the high dose of PTZ or BIC. The use of K rats as a possible new sensitive model of petit mal is discussed.