EIN-evoked Ca²⁺ signals are NMDA receptor-dependent.

<p><b>A</b> EIN stimulation evoked fluorescent Ca²⁺ signals in a motor neuron dendrite retrogradely filled with the Ca²⁺-sensitive dye, OGB1-dextran (5 mM), in the presence of NBQX (5 µM), glycine (1 µM), and strychnine (5 µM) in Mg²⁺-free ringer. Ca²⁺ signals were recorded before (black), during (dark grey) and after (light grey) the application of D/L-AP5 (100 µM). Pooled responses (Aii) demonstrate that D/L-AP5 significantly and reversibly abolishes NMDA receptor-induced changes in Ca²⁺ fluorescence. Error bars express ± SEM. <b>B</b> Image of the dendrite recorded in Ai. Localized EIN-evoked fluorescent change is shown in Bii (arrow, white). Scale bar = 20 µm. <b>C</b> Recording schematic: STIM = stimulating electrode, EIN = black, Ca²⁺-dye filled motor neuron = green.