Fig. 5.

Intracellular dialysis of GDP-β-S diminished modulation of HVA but not T-type Ca²⁺currents. A, In a cell loaded with GDP-β-S (2 mm), 5-HT produced reversible inhibition on T-type currents but had very little effect on the HVA currents; Aa, representative traces of the Ca²⁺ currents;Ab, graph showing amplitude of current versus time in the same cell. Symbols in graph correspond to those on the current traces. B, Summary of the effects of 5-HT on T-type currents and HVA currents in cells loaded with either GTP (control) or GDP-β-S.