Figure 7. PACAP-LTD properties.

A and B, application of PACAP-27 peptide (400 nm) induced an LTD that was blocked by a 45 min pretreatment of hippocampal slices with the EPAC inhibitor BFA (20 μm, n= 5, A), or the p38-MAPK inhibitor SB203580 (5 μm, n= 5, B), but not the PKA inhibitor H89 (2 μm) applied in the presence the PKC inhibitor GF109203X (0.5 μm, n= 5, B). C and D, after induction of LTD with 2 successive applications of 8-pCPT, PACAP-27 did not further decrease EPSP slope (C). Vice versa, LTD induced by 2 successive applications of PACAP was not significantly changed by a subsequent application of 8-pCPT (D). This shows mutual occlusion between Epac-LTD and PACAP-LTD (n= 5 in C and D).