A and B, cDNA derived from kidney (Ki, 5-day-old rats), superior cervical ganglion (SCG, 5-day-old rats) and neurone-enriched cell cultures from the SCG (CC, 5-day-old rats; cultures 3 days in vitro). Note that OCT3, OCTN1 and OCTN2, but not OCT1 or OCT2 mRNA is present in the SCG. C, single-cell RT-PCR from two representative neurones (1, 2) that were positive for the housekeeping gene, GAPDH (left panel). The same neurones also proved positive for OCT3 (right panel). D, RT-PCR products for OCT3, OCTN1 and OCTN2 determined in two different NGF-naïve PC12 cell cultures (PC12/a and PC12/b), and in rat dorsal root ganglia (DRG, 5-day-old rats). OCTN1 and OCTN2, but not OCT3 mRNA was detected in the rat DRG, though all were present in PC12 cultures.