Role of protein kinases A and C in the induction of mGluR-dependent long-term depression in the medial perforant path of the rat dentate gyrus in vitro

The involvement of protein kinases A and C in the induction of low frequenc y stimulation-induced long-term depression (LTD) in the medial perforant pa th of the dentate gyrus in vitro has been studied using the selective PKA i nhibitors H-89 and KT 5720 and PKC inhibitors Bisindolylmaleimide and Ro-31 -8220. The PKC inhibitors Bisindolylmaleimide I and Ro-31-8220 and the PKA inhibitors H-89 and KT5720 all partially inhibited LTD induction. However, the presence of both a PKC and a PKA inhibitor was necessary to completely block LTD induction. The induction of long-term potentiation was not blocke d by the inhibitors. It is suggested that the induction of LTD by LFS invol ves activation of PKC and PKA following activation of group I and group II metabotropic glutamate receptors (mGluR). (C) 1999 Published by Elsevier Sc ience Ireland Ltd. All rights reserved.