Cumulative data indicate no significant difference in extrasynaptic NMDA receptor-mediated current or Ca2+ responses between bicuculline and vehicle treated groups. Shown are various (A) current and (B, C) Ca2+ measurement parameters from responses of neurons to bath NMDA (100 μM) application following the synaptic blockade with MK-801 following overnight vehicle (black) and AP bursting (grey) treatment. All histograms show the mean and SEM. Electrophysiological measurements come from 9 vehicle and 10 AP bursting treated cells. Ca2+ imaging came from 5 vehicle and 6 AP bursting treated cells. No values were significantly different between treatment groups. (A) Peak current density was measured from the maximum macroscopic current amplitude divided by the whole cell capacitance. Charge transfer was measured from the integral of the current response with respect to baseline between response onset and return to baseline. (B) Ca2+ response amplitudes were measured with respect to baseline levels. Ca2+ response half width was calculated for the whole cell current measured from the left (on) and right (off) half of the response waveform with respect to the time point of the response peak at a level half way between baseline and response peak. (C) Nuclear and somatic Ca2+ concentrations at baseline and the NMDA response peak are shown for individual cells whereby each line connects values measured from the same cell.