TABLE 3.

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.