Effect of MPX-004 and MPX-007 on glutamate/glycine-induced currents in <i>Xenopus</i> oocytes expressing GluN1 and GluN2A, B, C, or D.

<p>Oocytes were exposed to MPX-004 or MPX-007 at concentrations from 10 nM to 10 μM as indicated. Inhibition curves were generated using GraphPad Prism and IC₅₀ values were generated using CCD Vault. The IC₅₀s for inhibition of GluN2A-mediated currents were 198 ± 17 and 143 ± 10 nM for MPX-004 and MPX-007, respectively. Each data point is a mean (± standard deviation) of data from 4–12 oocytes.</p

Effects of MPX-004 and MPX-007 on NMDA/glycine-induced currents of rat cortical neurons in primary culture.

<p>Cortical neurons were maintained in primary culture for 13–15 days and then examined using whole-cell manual patch clamp for current evoked by NMDA (100 μM) + glycine (10 μM) applied for 4 seconds during 10 second pulses to +20 or +40 mV from a holding potential of -70 mV. Inhibition of NMDA-activated currents was quantified during exposure to 10 μM MPX-007, MPX-004, Ro 25–6981, or a combination of Ro 25–6981 + MPX-004. Currents were blocked ~25–30% by either MPX-007 or MPX-004 alone, ~70% by Ro 25–6981 alone, and ~85% by Ro 25–6981 plus MPX-004.</p

Synthetic schemes for compounds 2–10.

<p>Synthetic schemes for compounds 2–10.</p

Effect of MPX-004 on isolated NMDA receptor-mediated fEPSPs in rat hippocampal CA1 stratum radiatum in response to stimulation of Schaffer collateral input.

<p>Slices were exposed to MPX-004 from 100 nM to 30 μM in half log concentration increments as well as to 50 μM. Right panel- Time course for inhibition of fEPSPs after application of different concentrations of MPX-004. Left panel- Percent inhibition at 40 min after application for each MPX-004 concentration. Maximum inhibition was approximately 60% of the fEPSPs at 30 or 50 μM. The IC₅₀ of MPX-004 for inhibition of fEPSPs was 3.4 μM. Curves in the right panel and data point in the left panel are a mean (± SEM) of 4, 5, 6, 8, 6, 5 and 2 slices obtained from 2, 2, 3, 3, 2, 2 and 1 rats exposed to 0.1, 0.3, 1, 3, 10, 30 and 50 μM MPX-004, respectively. In separate experiments, a highly selective GluN2B NAM inhibited approximately 40% of the fEPSP (data not shown).</p

Concentration-response of TCN-201, MPX-004, and MPX-007 inhibition of Ca²⁺ responses mediated by GluN2A expressed in HEK cells.

<p>Cells were stimulated with glutamate and glycine (3 μM each) in the presence of compounds at a range of concentrations. Curves for inhibition of the Ca²⁺ response in GluN2A-expressing cells were derived from fits to the Hill equation using GraphPad Prism (v6.00 for Mac, GraphPad Software, La Jolla California USA). Whereas MPX-004 and MPX-007 achieve full inhibition of the GluN2A Ca²⁺ response by ~ 3 μM, TCN-201 never inhibits more than ~40% of the response. Each data point is a mean (± standard deviation) of data from 20–86 experiments).</p

The structures of TCN-201, MPX-004 and MPX-007.

<p>The values are IC₅₀s for inhibition of Ca²⁺ responses mediated by GluN2A receptors expressed in HEK cells.</p