Long-term effects of neonatal seizures on subsequent N-methyl-D-aspartate receptor-1 and gamma-aminobutyric acid receptor A-alpha 1 receptor expression in hippocampus of the Wistar rat.

To evaluate the pathophysiological mechanism of subsequent reduced seizure threshold following neonatal seizures, single or recurrent prolonged seizures were induced to neonatal rats by the inhalant flurothyl. The expression of N-methyl-d-aspartate receptor 1 (NR1) and gamma-aminobutyric acid receptor A-alpha 1 (GABA-A-alpha 1) immunoreactivity in hippocampus were examined by Western blotting analysis at the day 7 (P7) and day 75 (P75) after the last seizure. Whereas there were no significant changes in single seizure group and recurrent seizure group of P75, NR1 expression enhanced significantly in P7 rats of recurrent seizure group. Meanwhile, polypeptide levels of GABA-A-alpha 1 receptor subunit decreased significantly in both single and recurrent seizure-treated P7 and P75 rats. Our results suggest that recurrent or single prolonged seizures during the neonatal period may have long-term effects on the balance between excitatory NMDA system and inhibitory GABA system in hippocampus of rats.