Summary of hypotheses related to inhibitory mechanisms
| Agent | Voltage Dependence | Comments | |
|---|---|---|---|
| Control | PNU-120596 | ||
| Mecamylamine | Net charge only | Strong | In the presence of the PAM, decreases open times and burst durations. Produces small-amplitude subconductance events. Most likely open channel block but produces some longer block times as well. |
| QX-314 | Strong | None | Fast channel blocker, no subconductance events. However, since burst durations are decreased, there must be some long block times as well. |
| Tetracaine | None | None | Most likely blocks both open and closed channels. Multiple forms of blockade suggested by closed times, the increase in burst frequency, and the appearance of subconductance states. |
| BTMPS | Net charge only | Peak only | Inhibition is use-dependent but not strongly voltage dependent. The longer channels are open, as in the presence of the PAM, the more likely they are to be blocked. |
| TMPH | Peak only | Strong | Likely to preferentially block open channels; however, the off-rate for α7 receptors is relatively fast compared with what has been reported for heteromeric channels. |
| tkP3BzPB | None | Weak | Probably not an open channel blocker. Shows preferential inhibition of the PNU-120596–potentiated receptors. Probably affects channels in both closed and open states. |