A sequential screning test based on the running component of audiogenic seizures in mice, including reference compound PD50 values.

1. The running component of audiogenic seizures in mice has been used as the basis of a sequential screening test for the detection of a variety of centrally acting drugs.2. For acceptance by the test, an active compound must completely suppress the running component in a total of sixteen mice at a dose of 1/5 LD50 intraperitoneally.3. Considerable economies in the numbers of animals required for screening have been achieved, the mean number of mice required to reject an inactive compound being 2.0.4. The running component is highly sensitive to anticonvulsants and general central depressants, and insensitive to phenothiazine tranquillizers and morphine. Reserpine caused an increase in the severity of the running component.5. The statistical model used in this test is of general application to screening test situations which use quantal data.