ATP efflux through CFTR. Acutely dissociated rat DRG neurons were transfected with the NC siRNA or the CFTR siRNA together with eGFP-expression vector to identify transfected cells. (A) Single-cell quantitative real-time RT-PCR. The expression level of the CFTR mRNA was normalized by the expression level of the GAPDH mRNA. In the graph, each value represents the mean (± SEM) normalized CFTR mRNA expression (CFTR mRNA/GAPDH mRNA)(n = 8 independent experiments). P value, unpaired t-test. (B) P2XR-NeSCCs recording. Outside-out patches were made from DRG neurons without transfection, and NeSCCs were monitored before and after treatment with NA (100 μM) in the presence and absence of PPADS (10 μM) by approaching the patch-electrode tip near to neurons transfected with the NC siRNA or the CFTR siRNA. Typical P2XR-NeSCCs are shown in the upper column. The holding potential was -70 mV. In the graph, the frequency of P2XR-NeSCCs was normalized by regarding the frequency before application with NA (Control) as 1 and each value represents the mean (± SEM) normalized event frequency (n = 6 independent patches). P values, Dunnett's test.