Ischemic tolerance affects the adenylation state of GluR2 mRNA

To analyse GluR2 regulations in the rat hippocampal CAI region following gl obal and tolerance-inducing ischemia in situ hybridization (ISH) and quanti tative PCR (Q-PCR) was applied. In addition, cDNA was synthesised from two different primer combinations in order to elucidate possible differences in the adenylation state of GluR2 mRNA. Following global ischemia, ISH and Q- PCR both showed reductions to half of control levels of GluR2 mRNA in conse nt with previously published results. Following tolerance induction, ISH sh owed no changes, whereas PCR analysis showed up-regulation to 228% of contr ol value for the general cDNA synthesis, and no change for the specific cDN A synthesis. This indicates that tolerance-inducing ischemia does not incre ase the amount of GluR2 mRNA; instead polyadenylation of the existing GluR2 mRNA pool takes place. NeuroReport 11:3279-3282 (C) 2000 Lippincott Willia ms & Wilkins.