RAPID INCREASE IN PKA ACTIVITY DURING LONG-TERM POTENTIATION IN THE HIPPOCAMPAL AFFERENT FIBER SYSTEM TO THE PREFRONTAL CORTEX IN-VIVO

The purpose of the present study was to examine whether cAMP-dependent protein kinase (PKA) was implicated in the process of long-term poten tiation (LTP) in the hippocampal afferent fibre system to the prefront al cortex in vivo. Using a biochemical approach, we measured PKA activ ity at different limes after induction of LTP. We show that there is a n NMDA receptor-dependent increase in PKA activity in the prefrontal c ortex, only at five minutes after LTP induction, These data demonstrat e a role of PKA in the induction and not the expression of cortical LT P and suggest that if PKA is involved in the late phase of LTP, it doe s not appear to be a persistent activation.