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Figure 4: Dose dependence of the effects of picrotoxin on L-LTP induced by 4xHFS. (a) Comparisons of the effects of picrotoxin (0.1, 1, 10, and 100 μM) on 4xHFS-induced L-LTP in euploid control-derived slices and (b) Ts65Dn-derived slices. Magnification of the final 10 minutes of recording. Colored lines represent the mean fEPSP slopes calculated for the last 10 minutes of recording. Representative fEPSP traces showing severe oscillations recorded from control-derived slices and Ts65Dn-derived slices after being exposed to picrotoxin. (c) Summary graph of euploid littermate control L-LTP data and (d) Ts65Dn L-LTP data (mean fEPSP slope during the last 10 min for each recording condition). 10 and 100 μM of picrotoxin rescued L-LTP to control levels in Ts65Dn-derived slices while causing severe oscillations in postsynaptic potentials. (e) Normalized data shows that 100 μM picrotoxin had a greater effect on Ts65Dn-derived slices compared to control slices. and are represented by and , respectively. Number of slices (animals) for control (without picro (), picro 0.1 μm (), picro 1 μm (), picro 10 μm (), and picro 100 μm ()) and Ts65Dn (without picro (), picro 0.1 μm (), picro 1 μm (), picro 10 μm (), and picro 100 μm ()). Error bars represent SEM. Arrows indicates LTP induction (4xHFS; with a 5 min intertrain intervals), representative traces show synaptic response during baseline (1) and at end of recording (2). Scale bars represent 2 mV (horizontal) and 10 ms (vertical).