on-off flickering

voltage-dependent block by proton

node of Ranvier

2-barrier model for proton block

well

outside

voltage-dependent block with TEA

K-depolarized squid giant axon

Time course of block by C9

squid giant axon

TTX-blocked iNa

internal C9 0.11 mM (nonyltriethylammonium)

Concentration-dependent block

internal TPeA (tetrapentylammonium)

+ 120 mV

Armstrong’s hypothesis for QA block

QA (quaternary ammonium)

use-dependent block with lidocaine

node of Ranvier, - 20 mV

internal NMS

(N-methylstrychnine)

QX-222 (quaternary lidocaine)

nicotinic AChR

frog sartorius muscle

-125 mV

-150mV

-120mV

-120mV

-150mV

multi-ion block in a long pore

selectivity filer

voltage-dependent multi-ion block

[K]o = 25 mM

flickering block by external Cs+

tunricate egg

Inward rectifier

200 mM [K]o

10 M [Cs]o

Long block dwell times with TTX and STX

batrachotoxin-Na channel, rat brain synaptosomes

symmetrical 200 mM NaCl, +50 mV