Figure 3.

Dialysis with GDP-β-S in EGFP-expressing neurons does not prevent the U-50488-mediated Ca²⁺ current inhibition, but the U-69593-mediated Ca²⁺ current inhibition is absent. A) Time course of Ca²⁺ current inhibition for prepulse (●) and postpulse (○) acquired from the sequential applications of U-69593 (10 μM) and U- 50488 (20 μM) where GDP-β-S (1 mM) was substituted for Na₂GTP in the pipette solution. B) Current traces and voltage paradigm employed to elicit Ca²⁺ currents for the cell in A. C) Summary bar graph showing the mean (± SE) Ca²⁺ current inhibition produced by application of U-69593 and U-50488 following dialysis with GDP-β-S. Numbers in parenthesis indicate the number of neurons tested.