Concentration dependence of NMDA-induced membrane potential oscillations in Hb9 interneurons. A,

<p>Whole-cell current-clamp recordings of membrane potential from a single Hb9 interneuron at several NMDA concentrations. Note the lowest NMDA concentration (6 μM) does not induce oscillations. <b>B–C,</b> NMDA dose-response curves for cycle frequency show a linear relation above 6 μM (r = 0.87, p<0.001, n = 20) and voltage amplitude (r = 0.92, p<0.001, n = 20). The threshold for oscillation activation is ∼9 μM. Data are normalized to 15 μM.