Fig. 1
TTX treatment induces synaptic plasticity in organotypic tissue cultures. (A) Representative image of an organotypic entorhino-hippocampal tissue culture stained with DAPI nuclear stain and post-hoc visualization of dentate granule cells and pyramidal neurons in CA1 and CA3. EC, entorhinal cortex; DG, dentate gyrus. Scale bar, 250 μm. (B) Post-hoc stained dentate granule cells (left image) and CA1 pyramidal neurons (right image). gcl, granule cell layer; ml, molecular layer; Scale bar dentate gyrus, 50 μm; Scale bar CA1, 100 μm. (C)-(D) Sample traces and group data of whole-cell patch-clamp recordings of AMPA-receptor mediated miniature excitatory postsynaptic currents (mEPSCs) in dentate granule cells (dGC). Treatment with TTX (2 µM, 2 days) induces synaptic strengthening reflected by a significant increase in mEPSC amplitudes and frequencies (D; mEPSC amplitude: control, 20.2 ± 0.51 pA; TTX, 21.9 ± 0.45 pA; mEPSC frequency: control, 0.521 ± 0.045 Hz; TTX, 1.32 ± 0.115 Hz; ncontrol = 37 cells in 7 cultures, nTTX = 39 cells in 7 cultures; Mann-Whitney test, RM two-way ANOVA for amplitude/frequency analysis). (E)-(F) Sample traces and group data of whole-cell patch-clamp recordings of AMPA-receptor mediated mEPSCs in CA1 pyramidal cells (CA1-PC). Treatment with TTX (2 µM, 2 days) induces synaptic strengthening reflected by a significant increase in mEPSC amplitudes and frequencies (F; mEPSC amplitude: control, 21.7 ± 0.53 pA; TTX, 23.7 ± 0.46 pA; mEPSC frequency: control, 0.925 ± 0.108 Hz; TTX, 1.94 ± 0.188 Hz; n = 20 cells in 4 cultures in each condition respectively; Mann-Whitney test, RM two-way ANOVA for amplitude/frequency analysis). Individual data points are indicated by gray dots. Values represent mean ± s.e.m. (*p < 0.05; **p < 0.01; ***p < 0.001)