Fig. 3.

HFS-LTP is inducible through activation of VDCC in Trpm4 ^−/− hippocampal neurons. a High-frequency stimulation (HFS 1-s burst at 100 Hz) of the Schaffer collateral pathway induced stronger CA1 LTP in controls (n = 8) as compared to Trpm4 ^−/− slices (n = 7). b Phosphorylation of CamKII before and after conditioning protocol (3 TBS) in WT and Trpm4 ^-/- slices detected by Western blotting of protein lysates from hippocampal CA1 region. c Application of 100 μM of the NMDAR blocker D-APV reduced HFS-induced potentiation significantly in WT (n = 4) but not in Trpm4 ^−/− (n = 4) LTP. d HFS-LTP in Trpm4 ^−/− (n = 5) was completely abolished by application of 100 μM of VDCC blocker nifedipine while WT still showed a significant potentiation (n = 5). e Summary of the effects of D-APV and nifedipine on LTP in Trpm4 ^−/− and WT