Developmental alteration in RNA metabolism of E1 mouse brain.

The contents of brain RNA rose rapidly until 14 days after birth and then dropped. They were lower in the E1 than in the non-convulsive mice between 56 and 100 days of life. The contents of acid-soluble UMP and their specific radioactivities, three hours after an intracranial injection of [3 H]-orotic acid, were not different in the same age of E1 and non-convulsive mouse brains. From four to 20 days after birth, the specific and relative specific radioactivities, representing the ratio of brain RNA synthesis, of the E1 mice were lower than those of the non-convulsive strains, while the E1 mice, applying convulsions once a week, exhibited higher values during the periods from 56 to 100 days of age as compared with the non-stimulated E1 or non-convulsive strains.