Carbon Dioxide Seizures in Immature Rats. ∗

Summary

The incidence of seizures caused by exposure to and withdrawal from CO₂ concentrations ranging between 5 and 50% was determined in adult rats and immature rats less than one month old. It was found that neither exposure nor withdrawal seizures could be elicited in animals less than 16 days of age, even though the same CO₂ atmospheres produced seizures in older animals. It was concluded that the lack of response of very young rats to CO₂ was primarily a manifestation of the general central nervous system immaturity of the infant rat, even though other factors, e.g., lack of CO₂ equilibration, might also affect the CO₂ response.