During the course of our research, we have found that the units used in the explanations of the Hodgkin and Huxley model in common textbooks often disagree. This can make it difficult for students looking at the model for the first time to get a good sense of what is going on. In an effort to help alleviate some of the confusion, below are some tables of valuesfound in Introduction to Biomedical Engineering, by John Enderle, Susan Blanchard, and Joseph Bronzino. Note that the alpha and beta values have units printed as 1/s. However, this is a typo in the text. Equations for alpha and beta values are actually given in units of 1/ms. Note that this text did not give an equation for bn. The text states that V represents the displacement from resting potentail and should therefore have a negative value. Further note that the equation for am is written as am = 0.01(V+25)/(exp((V+25)/10)-1), but should be written as am = 0.1(V+25)/(exp((V+25)/10)-1)*. Voltage constants for sodium, potassium, and leakage ions were based on these given in example problem 3.9 on page 126 of the Enderle text.

Introduction to Biomedical Engineering, by John Enderle, Susan Blanchard, and Joseph Bronzino

Symbol	Units	Quantity	Notes
GNa		0.12
GK		0.036
GL		0.0003
VNa		0.055V
VK		-0.072V
VL		-0.0494V
gNa
gK
gL
ah	1/ms		voltage dependences of the coefficients at 6.3 C
bh	1/ms		voltage dependences of the coefficients at 6.3 C
am	1/ms		voltage dependences of the coefficients at 6.3 C
bm	1/ms		voltage dependences of the coefficients at 6.3 C
an	1/ms		voltage dependences of the coefficients at 6.3 C
bn	1/ms
ho	1
th	ms
mo	1
tm	ms
no	1
tn	ms
Cm

Link to table of HH, Enderle, Scott, Hoppensteadt, Schwan, SI resources.