Seizure susceptibility and neurodegeneration induced by microinjection of kainic acid (KA) into the left amygdala (LA) in C57BL/6 and FVB/N mouse strains were compared. Mice were administered 0.5 microg of KA into the LA. Electroencephalograms (EEGs) and behavior were monitored for 48 h after KA microinjection. Neuronal cell damages in the CA1 and CA3 regions of hippocampus were assessed at 2 and 48 h after KA microinjection. We demonstrated that the FVB/N mice showed longer duration of seizure activity than the C57BL/6 mice in EEGs and behavioral observation. The C57BL/6 mice were resistant to neurodegeneration while the FVB/N mice were vulnerable as measured 2 and 48 h after KA microinjection. These differences might be associated with genetic background.