Figure 7
From: Transient ECM protease activity promotes synaptic plasticity
Inhibition of endogenous MMP-9 is required for LTP maintenance.
(A) The figure shows the time course of maximal EPSP slopes normalized to baseline measured in the CA1 area of the hippocampus. High-frequency stimulation in slices from WT rats that were treated with iaMMP-9 (open red circles; nrats = 5) evoked LTP at a similar level (180.2% ± 11.5% of baseline) as in untreated slices from wild type rats (filled gray circles; nrats = 6; p = 0.560 for the first 45 min after LTP induction). After approximately 45 min, LTP on slices from WT rats treated with iaMMP-9 declined to the level that was previously observed in slices from MMP-9 TG rats that were treated with DMSO (filled red squares; nrats = 6; p = 0.026, compared with untreated slices from wild type animals for the last 45 min of recording; p = 0.358, compared with untreated slices from MMP-9 TG rats). Black arrows mark the time of application of HFS. The open gray line marks the time when iaMMP-9 was present in the experimental solution. Error bars represent the SEM. (B) Representative traces of fEPSP 10 min before (black) and 15 and 90 min after (gray) LTP induction are shown. Scale bars = 2 mV and 5 ms.
