High oxygen pressure-induced convulsions in suckling mice.

Two hundred suckling mice from 20 litters were used for determining their functional development of the hyperoxic convulsion mechanism. It was found that 1 to 12-day-old mice did not develop convulsion when they were subjected to oxygen under high pressure. The hyperoxic convulsion was observed in 1 of 10 13-day-old (10%), 3 of 10 14-day-old (30%), 16 of 20 15-day-old (80%) and all of 16-day-old mice (100%). This finding indicates that the hyperoxic convulsion mechanism of the young mice takes 13-16 days for functional maturation. Besides, it was shown that hyperoxia could cause pulmonary damage, the incidence of which also increased with age of suckling mice.