Hyperexcitability following moderate hypoxia in hippocampal tissue slices.

The effects of moderate hypoxia on CA1 pyramidal cells were studied in submerged rat hippocampal tissue slices. Hyperexcitability developed during re-oxygenation following 30-45 min of hypoxia at 29 degrees C. During hypoxia a sustained increase in extracellular potassium was observed. The post-hypoxic hyperexcitability of CA1 neurons may be the result of their inability to fully recover intracellular potassium lost during oxygen deprivation.