EFFECTS OF PENTYLENETETRAZOL KINDLING ON GLUTAMATE-RECEPTOR GENES EXPRESSION IN THE RAT HIPPOCAMPUS

It has been hypothesized that changes in the excitatory amino acid rec eptor biosynthesis may be involved in the mechanism of kindling-an ani mal model of epileptogenesis. In order to test this hypothesis, we inv estigated the effects of pentylenetetrazol kindling on the expression of genes coding for NMDAR1 and GluR2 in the rat hippocampal formation. Pentylenetetrazol kindling decreased the hippocampal NMDAR1 mRNA leve l after 3 and 24 h; lowered the GluR2 flip level and elevated the flop mRNA one in the CAl field and dentate gyrus after 3 and 24 h, respect ively. A receptor autoradiography showed an increase in the [H-3]MK-80 1 binding density in the hippocampus following both acute and repeated pentylenetetrazol administration. We conclude that an early occurrenc e of downregulation of the glutamate receptor gene expression may be a n adaptive response of glutamate receptors to an oversupply of excitat ory amino acids during repeated seizures. (C) 1998 Elsevier Science B. V.