Differential effects of perinatal hypoxia and anoxia on long term seizure susceptibility in the rat.
We have previously demonstrated that hypoxia is acutely epileptogenic in the immature rat but not in the adult. The window during which hypoxia induces seizures in the rat ranges from postnatal day (P) 5-17, with the most severe seizures occurring at P10-12. Perinatal hypoxia resulted in significantly more acute seizure activity than perinatal anoxia. The present study evaluates the long term effects of perinatal hypoxia versus anoxia. Animals were exposed to hypoxia (3%O2) or anoxia (0%O2) at P10 and challenged later in adulthood (P55-60) with administration of pentylenetetrazol (PTZ) (45 mg/kg subcutaneously). Compared to normal littermate controls, the animals which had been exposed to perinatal hypoxia had a significantly higher frequency of generalized convulsions (GC) and a significantly shorter latency to the first myoclonic jerk (MJ) after PTZ. In contrast, perinatal anoxia did not alter long term seizure susceptibility. These results are discussed in context of previous studies which have shown variable long term effects using different models of perinatal hypoxia and/or ischemia.
Jensen
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FE
Department of Neurology, Children's Hospital, Harvard Medical School, Boston, MA 02115.
Applegate
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C
Burchfiel
J
J
Lombroso
C T
CT
D000818:Animals; D004198:Disease Susceptibility; D004562:Electrocardiography; D004569:Electroencephalography; D000860:Hypoxia / Q000150:complications*; D051381:Rats; D012640:Seizures / Q000209:etiology* / Q000503:physiopathology