Altered Na+-K+ ATPase immunoreactivity within GABAergic neurons in the gerbil hippocampal complex induced by spontaneous seizure and vigabatrin treatment

In the present study, the expression of Na+-K+ ATPase in the gerbil hippocampus associated with various sequelae of spontaneous seizures were investigated in order to identify the roles of Na+-K+ ATPase in the epileptogenesis and the recovery mechanisms in these animals. The population of Na+-K+ ATPase immunoreactive neurons and Na+-K+ ATPase immunodensity were significantly lower in the pre-seizure group of SS gerbils than those in SR gerbils. At 30-min postictal, the Na+-K+ ATPase immunoreactivity was significantly elevated in the hippocampal complex. At 3-h postictal, the Na+-K+ ATPase immunoreactivity in the hippocampus was declined, as compared to the 30-min postictal. At 12 h after seizure on-set, Na+-K+ ATPase expression was re-enhanced in the all regions of the hippocampal complex including the dentate hilus. Following administration of vigabatrin Na+-K+ ATPase expression was also increased. The present data suggest that altered Na+-K+ ATPase expression may contribute the regulation of the seizure activity in this animal. (C) 2003 Elsevier Ltd. All rights reserved.