24-Hour Periodicity and Audiogenic Convulsions in I Mice of Various Ages. ∗ †

Abstract

Summary

Daily rhythms were studied in I mice of several age groups under standardized experimental circumstances. The rhythms in eosinophil count and in rectal temperature are described for this stock. Moreover, 24-hour periodicities are noted for the susceptibility of I mice to audiogenic convulsions and for their ability to recover from convulsions. The magnitude of these differences was large and was statistically significant. In one group of young animals the convulsive risk was 11% by day and 63% by night and in another, 0% by day and 85% by night. Changes with age in several of the variables studied are also noted.