The Structure of the Cell Membrane Resting Membrane Potential

Goldman equation
The Goldman equation for M positive ionic species and A negative:
E
m
=
⎛
RT ⎜
ln⎜
F ⎜
⎝
∑
∑
[ ] + [ ]
+
M −
M P − A
[ ] [ ] ⎟ ⎟⎟
j
+
M −
M i + ∑ P − A
in j A j
j out ⎠
•E m = The membrane potential
•P ion = the permeability for that ion
•[ion] out = the extracellular concentration of that ion
•[ion] in = the intracellular concentration of that ion
•R = The ideal gas constant
•T = The temperature in kelvins
•F = Faraday's constant
N
i
N
i
P
P
M
M
+
i
+
i
i
out
A "Nernst-like" equation with terms for each permeant ion.
- All the ions are involved.
- Good agreement with the measured values (muscle cell: U measured=-92mV_U calc.=-89.2mV).
∑
j A j in
⎞