Abstract

The duration of the components of maximal seizures induced in mice by sound and by electroshock were measured and the two seizure patterns compared. Seven psychopharmacologic and two anticonvulsant drugs were tested for their ability to prevent the running component of maximal audiogenic seizures (MAS), to prevent the extensor component of both MAS and maximal electroshock seizures (MES), and to prolong the latency of MAS and MES.

The MAS and MES patterns are similar in that the major feature is a tonic convulsion char acterized by initial flexion and subsequent extension of the hindlegs; the duration of the tonic components of the two seizure patterns is remarkably similar. MAS differs from MES in that appreciable latency, wild running and clonus precede the tonic components. A period of clonus follows both MAS and MES.

Chlorpromazine, promazine, triflupromazine and hydroxyzine are not effective against MAS running or MES tonic-extension, but prevent the tonic-extensor component of MAS in doses near or slightly above the neurotoxic level. Neurotoxic doses of these four drugs are also required to increase MAS and MES latency. Reserpine actually increases seizure severity and decreases MES latency, and nearly all reserpine-treated mice die following the seizures. In nontoxic doses, meprobamate, phenaglycodol, phenoharbital and diphenylhydantoin prevent MAS running and MAS and MES tonic extension. These four drugs are most effective by the MAS tonic-extension test and they increase MAS latency. The significance of these results is discussed.