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.

