Congenerous expression of Fos and GFAP within hippocampus after kainic acid-induced seizures in rats

Objective To investigate the responses of neurons and astrocytes within the hippocampus (HI) to kainic acid (KA)-induced seizures in rats. Methods By means of anti-Fos protein and glial fibrillary acidic protein (GFAP) double immunofluorescence histochemical staining method combined with confocal laser-scanning microscopic technique, the regional and temporal distribution of reactive neurons and astrocytes in HI were observed at respective time after an unilateral stereotaxic microinjection of KA in the lateral ventricle of rats, previously shown to cause limbic and generalized convulsive seizures. Results The microinjection of KA elicited behavioral alterations including immobilization, staring, facial and jaw clonus, rearing, and falling, follovved by recurrent generalized convulsive seizures, and a pattern of obvious Fos and GFAP expression within HI. Double immunofluorescence histochemical staining showed that from 30 min to 2 h Fos and GFAP immunoreactivity was seen in HI, corresponding to the occurrence of motor expression of seizures. Conclusion The neurons and astrocytes in HI mightbe very activeduring seizures and there may be close relationship between reactive neurons and reactive astrocytes, whichmightplay an important role in epileptogenesis.