Parenteral penicillin model of epilepsy in the rat: a reappraisal

A parenteral penicillin model of epilepsy in the rat was investigated with the aim of evaluating its reliability. Behavioral and EEG patterns were strongly variable in a group of 100 rats injected with 1,000,000 IU/kg of penicillin i.p. Gross counts of spikes were Fourier transformed and grouped into two time windows in 24 out of the 100 rats. Analysis of variance applied to compare the two time windows showed a sufficient suitability of the phenomenon for antiepileptic drug testing purposes. Five subsequent injections of penicillin performed in 8 rats showed that a spontaneous decrease of the response takes place, preventing a crossover design in pharmacological analyses. Evans Blue studies demonstrated that there was not a breakdown of the blood-brain barrier; this model can be used for testing anticonvulsants unable to penetrate the blood-brain barrier.