Figure 5

Pregabalin does not appear to modulate caffeine-evoked Ca²⁺ release or Ca²⁺ homeostatic mechanisms. A & B) Show example records of Ca²⁺ transient evoked by caffeine (1 mM) applied to DRG neurones bathed in nominally Ca²⁺-free medium and measured using fura-2. Under these conditions the Ca²⁺ transients are only due to mobilisation of Ca²⁺ from intracellular stores. A) Illustrates a control caffeine response and B) shows a similar response to caffeine recorded in the presence of 25 μM pregabalin (PGB). C) Example trace showing an increase in K⁺-evoked Ca²⁺ flux by 25 μM pregabalin (PGB) in a DRG neurone bathed with choline chloride-based extracellular medium. The periods of stimulation with 30 mM KCl are shown with open bars and pregabalin application is shown with a filled bar. D) Example trace showing an increase in K⁺-evoked Ca²⁺ flux induced by 5 mM TEA in a DRG neurone bathed with standard NaCl-based extracellular medium. The periods of stimulation with 30 mM KCl are shown with open bars and TEA application is shown with a filled bar.