Dizocilpine pretreatment suppresses the action of hypoxia on hippocampal epileptic afterdischarges in immature rats

Effect of dizocilpine (0.5 mg/kg i.p.) on epileptic afterdischarges elicited by low-frequency electrical stimulation of the dorsal hippocampus was studied in rat pups aged 12 and 18 days. Repeated elicitation of afterdischarges (ADs) in control animals resulted in a progressive increase of the duration of ADs in both age groups. Dizocilpine (MK-801) injected after the first afterdischarge suppressed this prolongation in 12-day-old rats only. Hypobaric hypoxia (simulated altitude of 9000 m for one hour) led to a marked prolongation of the first afterdischarge in both age groups with a tendency to shorter ADs after repeated stimulations. Dizocilpine potentiated this tendency in 12-day-old rat pups so that it became statistically significant. Administration of dizocilpine before hypoxia prevented the increase in duration of the first afterdischarge in both age groups.