Figure 4.

Inhibition of the BC₃H1 AChR by single-cloned RNA aptamers. A combination (54) of the cell-flow (54) and whole-cell current-recording (69) techniques was used at a membrane potential of −60 mV at 22°C in BC₃H1 buffer, pH 7.4. The whole-cell currents were generated by 100 μM carbamoylcholine after 2-sec preincubation with 0.1 μg/μl tRNA and 0.3 unit/μl anti-RNase alone (A), plus 5 μM SELEX pool 0 (B), plus 5 μM class II aptamer 3 (C), plus 100 μM cocaine (D), and plus 0.5 μM class I aptamer 14 (E). The lines parallel to the abscissa represent currents corrected for receptor desensitization (54).