Figure 7. Removal of extracellular Ca²⁺ from culture media prevented the increase in cytotoxicity for cells expressing CNGB3 F525N. Bar graph of the relative cytotoxicity for channel-expressing cells treated with 0.1 μM CPT-cGMP in normal or Ca²⁺-free Dulbecco’s modified Eagle’s medium media (n=12; *, p<0.05). The dashed line indicates the level of cytotoxicity in control cells expressing pOPRSVI plasmid alone cultured in normal media without CPT-cGMP.