Electroencephalographic frequency patterns of rats treated with aminopterin in early infancy.

Aminopterin was given to dams on the 4th, 10th and 18th days after delivery and to offsprings on the 18th day of life, and the frequency analysis of electroencephalograms of the offsprings was done at the age of 3, 4, 5, 6 and 7 weeks. A definite delay of maturation of the brain function was observed in rats treated with aminopterin when EEG was examined at the age of 5, 6 and 7 weeks. In this study an analyzer of basic waves of electroencephalograms was specially prepared so as to be able to observe slight changes in areas with slow waves.