Activation of a K‐252b‐Sensitive Protein Kinase is Necessary for a Post‐Synaptic Phase of Long‐Term Potentiation in Area CA1 of Rat Hippocampus

Abstract

K-252b, a potent inhibitor of protein kinases blocked a late phase of long-term potentiation (LTP) in area CA1 of rat hippocampal slices, resulting in decremental LTP. It also prevented the slowly developing increase in sensitivity of CA1 neurons to iontophoretically administered α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) which was seen in control slices that exhibit nondecremental LTP. However, K-252b applied 60–180 min after the induction of LTP had no effect on the potentiated synaptic and AMPA-induced responses. A K-252b-sensitive protein kinase may therefore be involved in a slowly developing postsynaptic component of LTP.