Fig 5.

CO₂ inhibition of KCl-mediated elevation of intra-cellular calcium levels. Relative intracellular calcium levels in cultured trigeminal ganglion neurons incubated in isohydric medium in response to CO₂ exposure and stimulated with 60 mM KCl (A), or stimulated with KCl before and after exposure to compressed air (B). The levels are the average of all the cells in each well. A representative graph from ≥6 independent experiments is shown. All data are expressed relative to basal calcium levels, which were made equal to 1.