Fig. 3
Synaptically released glutamate does not contribute to GNE-8324 potentiation. a Submaximal d-APV concentrations eliminates GNE-8324 potentiation in inhibitory neurons. Sample traces of NMDAR EPSCs in inhibitory neurons before and after GNE-8324 application in 0, 3, or 10 μM d-APV. Scale bars, 20 pA/100 ms. Dependence of GNE-8324 potentiation on d-APV concentrations. No PAM (GNE-8324) control (Veh with 0 μM d-APV) shown at the far right. N = 7, 5, 9, 3, 7, 5 for 0, 1, 3, 5, 10 μM d-APV and no PAM. All compared to 0 μM d-APV. *P < 0.05; EPSC area. #P < 0.05; ##P < 0.01, one-way ANOVA with Dunnett's correction. EPSC peak amplitude. b Similar blockade of AMPAR EPSCs by γ-DGG in excitatory and inhibitory neurons. Sample traces of AMPAR EPSCs in the absence and presence of γ-DGG in inhibitory (Int) and excitatory (Ext) neurons. Scale bars, 50 pA/20 ms. Similar blockade of AMPAR EPSC peak and area by γ-DGG in excitatory and inhibitory neurons across a range of γ-DGG concentrations (0.2, 0.6, and 1.5 mM). 32.21 ± 12.14% (Peak, Ext, 0.2 mM; mean ± SEM), 30.06 ± 5.62% (Peak, Int, 0.2 mM), P = 0.88; 34.34 ± 6.22% (Peak, Ext, 0.6 mM), 38.57 ± 6.45% (Peak, Int, 0.6 mM), P = 0.66; 42.71 ± 7.78% (Peak, Ext, 1.5 mM), 46.86 ± 6.47% (Peak, Int, 1.5 mM), P = 0.56, 23.08 ± 10.13% (Area, Ext, 0.2 mM), 32.28 ± 6.44% (Area, Int, 0.2 mM), P = 0.47; 34.55 ± 10.15% (Area, Ext, 0.6 mM), 42.09 ± 7.23% (Area, Int, 0.6 mM), P = 0.60; 38.16 ± 9.03% (Area, Ext, 1.5 mM), 49.67 ± 7.24% (Area, Int, 1.5 mM), P = 0.39, unpaired t test. c Spontaneous release of synaptic glutamate does not contribute significantly to GNE-8324 potentiation in inhibitory neurons. Elevating [Ca2+]Ext from 2 to 4 or 6 mM did not significantly increase sEPSC frequency in excitatory neurons. 1.32 ± 0.30 Hz (2 mM), 1.44 ± 0.39 Hz (4 mM), 1.54 ± 0.24 Hz (6 mM); N = 8, 8, 4. Reducing [Ca2+]Ext from 2 to 1 or 0.5 mM reduced sEPSC frequency in inhibitory neurons (2.01 ± 0.48 Hz (0.5 mM), 1.50 ± 0.33 Hz (1 mM), 3.08 ± 1.16 Hz (2 mM); N = 12, 8, 8). d Significant GNE-8324 potentiation in inhibitory neurons at 1 mM [Ca2+]Ext. Scale bars, 50 pA/50 ms. Error bars represent SEM
