Antipentylenetetrazol action of clobazam in developing rats

Clobazam (0.5 to 7.5 mg/kg i.p.) was tested against motor seizures elicited by pentylenetetrazol in rats 7, 12, 18, 25 and 90 days old. Minimal, predo minantly clonic seizures with preserved righting ability were reliably indu ced by pentylenetetrazol and suppressed by clobazam in rats aged Is days or more. The incidence of minimal seizures after clobazam pretreatment was no t increased in 7- and 12-day-old rat pups. Generalized tonic-clonic seizure s were markedly suppressed by clobazam in all age groups. In 18-day-old and older animals clobazam doses suppressing generalized seizures were always lower than those necessary for exerting an effect on minimal seizures. The differences in clobazam action appearing at various levels of maturation ar e only quantitative.